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NASA NTRS2000

Pulmonary Toxicity of Simulated Lunar and Martian Dusts Intratracheally Instilled into Mice

The National Aeronautics and Space Administration (NASA) is contemplating sending humans to Mars and to the Moon for further exploration. Equipment designated for these extraterrestrial bases will require testing in simulated Martian or lunar environments. The properties of Hawaiian and San Francisco Mountain volcanic ashes make them suitable to be used in these test environments as Martian and lunar dust simulants, respectively. The present toxicity study was conducted to address NASA's concern about the health risk of dust exposures in the test facilities. In addition, the results obtained on these simulants can be used to design a toxicity study of actual moon dust and Martian dust, which will probably be available in a few years. Respirable portions of lunar soil simulant (LSS) and Martian soil simulant (MSS) were separated from their respective raw materials. These soil simulants, together- with fine titanium dioxide (negative control for fibrogenesis in mice), and crystalline silica (positive control) were each intratracheally instilled in saline to groups of 4 male mice (C57BL/6J, 2-3 months old) at 0.1 mg/mouse (LD) or lmg/mouse (HD). The lungs were harvested 7 or 90 days after the single dust treatment for histopathological examination. Lungs of the LSS-LD groups on either the 7- or 90-day study showed no evidence of inflammation, edema, or fibrosis. Clumps of particles and an increased number of macrophages, visible in the lungs examined after 7 days, were absent after 90 days. The LSS-HD-7d group showed mild to moderate alveolitis with neutrophilic and lymphocytic infiltration, and mild perivascular and peribronchiolar inflammation. The LSS-HD-90d group showed signs of chronic inflammation: septal thickening, mild perivascular and peribronchiolar inflammation, mild alveolitis and some fibrosis. Foci of particle-laden macrophages (PLMs) were still visible. Lungs of the MSS-LD-7d group revealed mild focal intraalveolar inflammation with neutrophilic and lymphocytic infiltration, and mild perivascular and peribronchiolar inflammation. The MSS-LD-90d group showed PLMs and scattered foci of mild fibrosis. The MSS-HD-7d group showed large foci of PLMs, intraalveolar debris, mild to moderate focal alveolitis, and mild to moderate perivascular and peribronchiolar inflammation. The MSS-HD-90d group showed focal chronic mild to moderate alveolitis and fibrosis. To mimic the oxidative and reactive properties of Martian surface dust in the test animals, groups of 4 mice were exposed to ozone (0.5 ppm for 3 hours) prior to instillation of the MSS. Lung lesions in the MSS groups were more severe with the ozone pretreatment. The O3-MSS-HD-90d group had wide spread intraalveolar debris, focal moderate alveolitis and fibrosis. The results for the titanium dioxide and quartz controls were consistent with the known pulmonary toxicity of these compounds. The overall severity of toxic injury to the lungs was TiO2<LSS<MSS<MSS+O3<quartz. In general, the toxic responses increased with the increase of dust burden in the lung. Except for TiO2, the increased duration of dust presence in the lung from 7 to 90 days transformed the acute inflammatory response to a chronic inflammatory lesion.

Lam, Chiu-Wing↗
DOE OSTI2020

Materials Data on KBa6Zn4(GaO3)7 by Materials Project

KBa6Zn4(GaO3)7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.87–2.97 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.89–2.97 Å. There are twelve inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with two BaO6 octahedra, corners with two ZnO4 tetrahedra, corners with seven GaO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Ba–O bond distances ranging from 2.64–2.83 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.57–2.87 Å. In the third Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.58–2.87 Å. In the fourth Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with two BaO6 octahedra, corners with two ZnO4 tetrahedra, corners with seven GaO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Ba–O bond distances ranging from 2.65–2.82 Å. In the fifth Ba2+ site, Ba2+ is bonded to six O2- atoms to form BaO6 octahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, corners with six GaO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 74–76°. There are a spread of Ba–O bond distances ranging from 2.64–2.82 Å. In the sixth Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.56–2.86 Å. In the seventh Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.61–2.85 Å. In the eighth Ba2+ site, Ba2+ is bonded to six O2- atoms to form BaO6 octahedra that share corners with two BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, corners with eight GaO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Ba–O bond distances ranging from 2.65–2.79 Å. In the ninth Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.59–2.83 Å. In the tenth Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with two BaO6 octahedra, corners with two ZnO4 tetrahedra, corners with seven GaO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 73–76°. There are a spread of Ba–O bond distances ranging from 2.62–2.83 Å. In the eleventh Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.57–2.83 Å. In the twelfth Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 octahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, corners with six GaO4 tetrahedra, and an edgeedge with one GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 73–74°. There are a spread of Ba–O bond distances ranging from 2.69–2.79 Å. There are eight inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, and corners with four GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 70–84°. There are a spread of Zn–O bond distances ranging from 1.96–2.09 Å. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share a cornercorner with one BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, corners with four GaO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 74°. There are a spread of Zn–O bond distances ranging from 1.97–2.10 Å. In the third Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share a cornercorner with one BaO6 octahedra, corners with five GaO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Zn–O bond distances ranging from 1.96–2.08 Å. In the fourth Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, and corners with four GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 70–81°. There are a spread of Zn–O bond distances ranging from 1.98–2.02 Å. In the fifth Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share a cornercorner with one BaO6 octahedra, corners with five GaO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 74°. There are a spread of Zn–O bond distances ranging from 1.96–2.06 Å. In the sixth Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share a cornercorner with one BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, corners with four GaO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 75°. There are a spread of Zn–O bond distances ranging from 1.97–2.09 Å. In the seventh Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share a cornercorner with one BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, corners with four GaO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 73°. There are a spread of Zn–O bond distances ranging from 1.98–2.06 Å. In the eighth Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with two BaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, and corners with five GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 70–71°. There are a spread of Zn–O bond distances ranging from 1.97–2.02 Å. There are fourteen inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 64–66°. There are a spread of Ga–O bond distances ranging from 1.85–1.94 Å. In the second Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 65–67°. There are a spread of Ga–O bond distances ranging from 1.85–1.94 Å. In the third Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra and corners with three ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–44°. There is three shorter (1.86 Å) and one longer (1.95 Å) Ga–O bond length. In the fourth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six BaO6 octahedra, a cornercorner with one GaO4 tetrahedra, and corners with two ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–70°. There are a spread of Ga–O bond distances ranging from 1.86–1.93 Å. In the fifth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 66–69°. There are a spread of Ga–O bond distances ranging from 1.85–1.94 Å. In the sixth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra, corners with two ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 69–81°. There are a spread of Ga–O bond distances ranging from 1.86–1.91 Å. In the seventh Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra, corners with two ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 69–81°. There are a spread of Ga–O bond distances ranging from 1.86–1.91 Å. In the eighth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are a spread of Ga–O bond distances ranging from 1.85–1.92 Å. In the ninth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with two BaO6 octahedra, corners with three ZnO4 tetrahedra, and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 67–69°. There are a spread of Ga–O bond distances ranging from 1.85–1.92 Å. In the tenth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra, a cornercorner with one GaO4 tetrahedra, and corners with two ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–46°. There are a spread of Ga–O bond distances ranging from 1.84–1.94 Å. In the eleventh Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra, corners with two GaO4 tetrahedra, and corners with three ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 70–82°. There are a spread of Ga–O bond distances ranging from 1.87–1.90 Å. In the twelfth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three BaO6 octahedra, corners with two GaO4 tetrahedra, and corners with three ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 66–79°. There are a spread of Ga–O bond distances ranging from 1.85–1.92 Å. In the thirteenth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share a cornercorner with one BaO6 octahedra, corners with two GaO4 tetrahedra, corners with three ZnO4 tetrahedra, and an edgeedge with one BaO6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are a spread of Ga–O bond distances ranging from 1.86–1.91 Å. In the fourteenth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six BaO6 octahedra and corners with three GaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 62–67°. There are a spread of Ga–O bond distances ranging from 1.85–1.90 Å. There are forty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+ and two Ga3+ atoms. In the second O2- site, O2- is bonded to two Ba2+, one Zn2+, and one Ga3+ atom to form distorted OBa2ZnGa tetrahedra that share corners with five OBa3Ga tetrahedra and a cornercorner with one OKBa3Ga trigonal bipyramid. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Zn2+, and two Ga3+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to one K1+, two Ba2+, and two Zn2+ atoms. In the fifth O2- site, O2- is bonded to two Ba2+, one Zn2+, and one Ga3+ atom to form distorted OBa2ZnGa tetrahedra that share corners with six OBa3Ga tetrahedra and a cornercorner with one OKBa3Ga trigonal bipyramid. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+, one Zn2+, and one Ga3+ atom. In the seventh O2- sit

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm4AlSi5(NO)7 by Materials Project

Sm4AlSi5(NO)7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to four N3- and four O2- atoms. There are a spread of Sm–N bond distances ranging from 2.32–2.97 Å. There are a spread of Sm–O bond distances ranging from 2.30–3.06 Å. In the second Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to four N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.31–2.67 Å. There are a spread of Sm–O bond distances ranging from 2.43–2.73 Å. In the third Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to four N3- and one O2- atom. There are a spread of Sm–N bond distances ranging from 2.20–2.55 Å. The Sm–O bond length is 2.70 Å. In the fourth Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to three N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.28–2.63 Å. There are a spread of Sm–O bond distances ranging from 2.34–2.54 Å. In the fifth Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to three N3- and four O2- atoms. There are a spread of Sm–N bond distances ranging from 2.39–2.67 Å. There are a spread of Sm–O bond distances ranging from 2.25–2.77 Å. In the sixth Sm3+ site, Sm3+ is bonded in a 9-coordinate geometry to six N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.46–2.86 Å. There are a spread of Sm–O bond distances ranging from 2.38–2.78 Å. In the seventh Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to three N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.23–2.58 Å. There are a spread of Sm–O bond distances ranging from 2.31–2.53 Å. In the eighth Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to six N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.49–2.85 Å. There are one shorter (2.32 Å) and one longer (2.38 Å) Sm–O bond lengths. In the ninth Sm3+ site, Sm3+ is bonded in a 4-coordinate geometry to six N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.35–2.97 Å. There are one shorter (2.44 Å) and one longer (2.60 Å) Sm–O bond lengths. In the tenth Sm3+ site, Sm3+ is bonded in a 4-coordinate geometry to four N3- and one O2- atom. There are a spread of Sm–N bond distances ranging from 2.32–2.69 Å. The Sm–O bond length is 2.42 Å. In the eleventh Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to five N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.38–2.69 Å. There are one shorter (2.27 Å) and one longer (2.80 Å) Sm–O bond lengths. In the twelfth Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to five N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.44–2.58 Å. There are a spread of Sm–O bond distances ranging from 2.45–2.81 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a 5-coordinate geometry to one N3- and four O2- atoms. The Al–N bond length is 1.97 Å. There are a spread of Al–O bond distances ranging from 1.85–1.98 Å. In the second Al3+ site, Al3+ is bonded to three N3- and one O2- atom to form distorted AlN3O tetrahedra that share a cornercorner with one SiN2O2 tetrahedra. There are a spread of Al–N bond distances ranging from 1.87–2.01 Å. The Al–O bond length is 1.77 Å. In the third Al3+ site, Al3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Al–O bond distances ranging from 1.82–1.87 Å. There are fifteen inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to one N3- and two O2- atoms. The Si–N bond length is 1.77 Å. There is one shorter (1.69 Å) and one longer (1.70 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to two N3- and two O2- atoms. There is one shorter (1.67 Å) and one longer (1.75 Å) Si–N bond length. There is one shorter (1.67 Å) and one longer (1.69 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded in a T-shaped geometry to one N3- and two O2- atoms. The Si–N bond length is 2.01 Å. There is one shorter (1.73 Å) and one longer (1.82 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded in a 5-coordinate geometry to two N3- and three O2- atoms. There is one shorter (1.80 Å) and one longer (1.82 Å) Si–N bond length. There are a spread of Si–O bond distances ranging from 1.69–2.20 Å. In the fifth Si4+ site, Si4+ is bonded in a bent 120 degrees geometry to one N3- and one O2- atom. The Si–N bond length is 1.83 Å. The Si–O bond length is 1.65 Å. In the sixth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two N3- and one O2- atom. There is one shorter (1.76 Å) and one longer (1.80 Å) Si–N bond length. The Si–O bond length is 1.64 Å. In the seventh Si4+ site, Si4+ is bonded in a distorted trigonal non-coplanar geometry to two N3- and one O2- atom. There is one shorter (1.75 Å) and one longer (1.85 Å) Si–N bond length. The Si–O bond length is 1.68 Å. In the eighth Si4+ site, Si4+ is bonded in a T-shaped geometry to two N3- and one O2- atom. There is one shorter (1.79 Å) and one longer (1.82 Å) Si–N bond length. The Si–O bond length is 1.72 Å. In the ninth Si4+ site, Si4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.67–1.73 Å. In the tenth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. In the eleventh Si4+ site, Si4+ is bonded in a see-saw-like geometry to two N3- and two O2- atoms. There is one shorter (1.74 Å) and one longer (1.85 Å) Si–N bond length. There is one shorter (1.72 Å) and one longer (1.77 Å) Si–O bond length. In the twelfth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to one N3- and two O2- atoms. The Si–N bond length is 1.71 Å. There is one shorter (1.66 Å) and one longer (1.70 Å) Si–O bond length. In the thirteenth Si4+ site, Si4+ is bonded to two N3- and two O2- atoms to form corner-sharing SiN2O2 trigonal pyramids. There is one shorter (1.74 Å) and one longer (1.78 Å) Si–N bond length. There is one shorter (1.80 Å) and one longer (1.94 Å) Si–O bond length. In the fourteenth Si4+ site, Si4+ is bonded in a tetrahedral geometry to two N3- and two O2- atoms. There is one shorter (1.71 Å) and one longer (1.78 Å) Si–N bond length. There is one shorter (1.65 Å) and one longer (1.72 Å) Si–O bond length. In the fifteenth Si4+ site, Si4+ is bonded to two N3- and two O2- atoms to form SiN2O2 tetrahedra that share a cornercorner with one AlN3O tetrahedra and a cornercorner with one SiN2O2 trigonal pyramid. There is one shorter (1.70 Å) and one longer (1.77 Å) Si–N bond length. There is one shorter (1.67 Å) and one longer (1.69 Å) Si–O bond length. There are twenty-one inequivalent N3- sites. In the first N3- site, N3- is bonded in a 1-coordinate geometry to four Sm3+ and one Si4+ atom. In the second N3- site, N3- is bonded in a 1-coordinate geometry to four Sm3+ and one Al3+ atom. In the third N3- site, N3- is bonded in a distorted bent 120 degrees geometry to two Sm3+ and two Si4+ atoms. In the fourth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.49 Å. In the fifth N3- site, N3- is bonded in a 2-coordinate geometry to two Sm3+ and two Si4+ atoms. In the sixth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Si4+, and one N3- atom. In the seventh N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.48 Å. In the eighth N3- site, N3- is bonded in a 2-coordinate geometry to one Sm3+, two Si4+, and one N3- atom. The N–N bond length is 1.48 Å. In the ninth N3- site, N3- is bonded in a 5-coordinate geometry to three Sm3+, one Al3+, and one N3- atom. In the tenth N3- site, N3- is bonded in a distorted single-bond geometry to three Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.54 Å. In the eleventh N3- site, N3- is bonded in a 4-coordinate geometry to three Sm3+ and one N3- atom. The N–N bond length is 1.45 Å. In the twelfth N3- site, N3- is bonded in a 2-coordinate geometry to one Sm3+, two Si4+, and one N3- atom. In the thirteenth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Si4+, and one N3- atom. In the fourteenth N3- site, N3- is bonded in a 2-coordinate geometry to two Sm3+, one Al3+, one Si4+, and one N3- atom. The N–N bond length is 1.49 Å. In the fifteenth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.50 Å. In the sixteenth N3- site, N3- is bonded in a 4-coordinate geometry to two Sm3+, one Al3+, and one N3- atom. In the seventeenth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. In the eighteenth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Si4+, and one N3- atom. In the nineteenth N3- site, N3- is bonded in a distorted trigonal pyramidal geometry to three Sm3+ and one Si4+ atom. In the twentieth N3- site, N3- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the twenty-first N3- site, N3- is bonded in a 2-coordinate geometry to two Sm3+ and two Si4+ atoms. There are twenty-one inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Sm3+ and one Al3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Sm3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Sm3+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to one Sm3+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Sm3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Sm3+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sm3+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+ and two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+, one Al3+, and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca9Mn(PO4)7 by Materials Project

Ca9Mn(PO4)7 crystallizes in the trigonal R3c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.65 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.79 Å. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.68 Å. Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six PO4 tetrahedra. There are three shorter (2.12 Å) and three longer (2.14 Å) Mn–O bond lengths. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.53 Å) and three longer (1.57 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Mn3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Mn3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm4AlSi5(NO)7 by Materials Project

Sm4AlSi5(NO)7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to three N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.31–2.72 Å. There are a spread of Sm–O bond distances ranging from 2.31–2.42 Å. In the second Sm3+ site, Sm3+ is bonded in a 4-coordinate geometry to three N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.31–2.85 Å. There are one shorter (2.42 Å) and one longer (2.48 Å) Sm–O bond lengths. In the third Sm3+ site, Sm3+ is bonded in a 5-coordinate geometry to four N3- and one O2- atom. There are a spread of Sm–N bond distances ranging from 2.19–2.54 Å. The Sm–O bond length is 2.66 Å. In the fourth Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to three N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.27–2.54 Å. There are a spread of Sm–O bond distances ranging from 2.39–2.49 Å. In the fifth Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to two N3- and four O2- atoms. There are one shorter (2.39 Å) and one longer (2.59 Å) Sm–N bond lengths. There are a spread of Sm–O bond distances ranging from 2.29–2.42 Å. In the sixth Sm3+ site, Sm3+ is bonded in a 9-coordinate geometry to six N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.48–2.93 Å. There are a spread of Sm–O bond distances ranging from 2.35–2.66 Å. In the seventh Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to three N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.21–2.45 Å. There are a spread of Sm–O bond distances ranging from 2.31–2.63 Å. In the eighth Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to five N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.43–2.81 Å. There are one shorter (2.30 Å) and one longer (2.42 Å) Sm–O bond lengths. In the ninth Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to five N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.23–2.94 Å. There are one shorter (2.38 Å) and one longer (2.61 Å) Sm–O bond lengths. In the tenth Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to five N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.30–3.03 Å. There are one shorter (2.36 Å) and one longer (2.98 Å) Sm–O bond lengths. In the eleventh Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to five N3- and two O2- atoms. There are a spread of Sm–N bond distances ranging from 2.40–2.62 Å. There are one shorter (2.28 Å) and one longer (2.63 Å) Sm–O bond lengths. In the twelfth Sm3+ site, Sm3+ is bonded in a 8-coordinate geometry to five N3- and three O2- atoms. There are a spread of Sm–N bond distances ranging from 2.40–2.68 Å. There are a spread of Sm–O bond distances ranging from 2.51–2.79 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a distorted trigonal bipyramidal geometry to one N3- and four O2- atoms. The Al–N bond length is 1.90 Å. There are a spread of Al–O bond distances ranging from 1.82–2.17 Å. In the second Al3+ site, Al3+ is bonded to three N3- and one O2- atom to form AlN3O tetrahedra that share a cornercorner with one SiN2O2 tetrahedra and a cornercorner with one SiN3O trigonal pyramid. There is two shorter (1.89 Å) and one longer (2.02 Å) Al–N bond length. The Al–O bond length is 1.80 Å. In the third Al3+ site, Al3+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Al–O bond distances ranging from 1.80–1.87 Å. There are fifteen inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to one N3- and two O2- atoms. The Si–N bond length is 1.75 Å. There is one shorter (1.66 Å) and one longer (1.69 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to two N3- and two O2- atoms. There is one shorter (1.67 Å) and one longer (1.73 Å) Si–N bond length. There is one shorter (1.66 Å) and one longer (1.70 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded in a water-like geometry to two O2- atoms. There is one shorter (1.68 Å) and one longer (1.70 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded to two N3- and two O2- atoms to form corner-sharing SiN2O2 tetrahedra. There is one shorter (1.78 Å) and one longer (1.79 Å) Si–N bond length. There is one shorter (1.64 Å) and one longer (1.71 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded in a water-like geometry to one N3- and one O2- atom. The Si–N bond length is 1.82 Å. The Si–O bond length is 1.66 Å. In the sixth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two N3- and one O2- atom. There is one shorter (1.76 Å) and one longer (1.81 Å) Si–N bond length. The Si–O bond length is 1.66 Å. In the seventh Si4+ site, Si4+ is bonded in a distorted trigonal non-coplanar geometry to two N3- and one O2- atom. There is one shorter (1.72 Å) and one longer (1.89 Å) Si–N bond length. The Si–O bond length is 1.68 Å. In the eighth Si4+ site, Si4+ is bonded to three N3- and one O2- atom to form distorted SiN3O trigonal pyramids that share a cornercorner with one AlN3O tetrahedra and a cornercorner with one SiN2O2 tetrahedra. There are a spread of Si–N bond distances ranging from 1.79–2.07 Å. The Si–O bond length is 1.81 Å. In the ninth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.69–1.73 Å. In the tenth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. In the eleventh Si4+ site, Si4+ is bonded in a see-saw-like geometry to two N3- and two O2- atoms. There is one shorter (1.77 Å) and one longer (1.90 Å) Si–N bond length. There is one shorter (1.71 Å) and one longer (1.82 Å) Si–O bond length. In the twelfth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to one N3- and two O2- atoms. The Si–N bond length is 1.71 Å. There is one shorter (1.68 Å) and one longer (1.72 Å) Si–O bond length. In the thirteenth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two N3- and one O2- atom. There is one shorter (1.71 Å) and one longer (1.72 Å) Si–N bond length. The Si–O bond length is 1.68 Å. In the fourteenth Si4+ site, Si4+ is bonded in a tetrahedral geometry to two N3- and two O2- atoms. There is one shorter (1.70 Å) and one longer (1.77 Å) Si–N bond length. There is one shorter (1.65 Å) and one longer (1.69 Å) Si–O bond length. In the fifteenth Si4+ site, Si4+ is bonded to two N3- and two O2- atoms to form SiN2O2 tetrahedra that share a cornercorner with one AlN3O tetrahedra. There is one shorter (1.69 Å) and one longer (1.79 Å) Si–N bond length. Both Si–O bond lengths are 1.68 Å. There are twenty-one inequivalent N3- sites. In the first N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the second N3- site, N3- is bonded in a 2-coordinate geometry to three Sm3+, one Al3+, and one Si4+ atom. In the third N3- site, N3- is bonded in a 2-coordinate geometry to two Sm3+ and two Si4+ atoms. In the fourth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+ and one Si4+ atom. In the fifth N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Sm3+ and two Si4+ atoms. In the sixth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the seventh N3- site, N3- is bonded in a 4-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.48 Å. In the eighth N3- site, N3- is bonded in a 2-coordinate geometry to two Si4+ and one N3- atom. The N–N bond length is 1.51 Å. In the ninth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Al3+, and one N3- atom. In the tenth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+ and one Si4+ atom. In the eleventh N3- site, N3- is bonded in a 4-coordinate geometry to three Sm3+ and one N3- atom. The N–N bond length is 1.45 Å. In the twelfth N3- site, N3- is bonded in a 2-coordinate geometry to one Sm3+, two Si4+, and one N3- atom. In the thirteenth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the fourteenth N3- site, N3- is bonded in a 1-coordinate geometry to three Sm3+, one Al3+, and one N3- atom. The N–N bond length is 1.53 Å. In the fifteenth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. The N–N bond length is 1.55 Å. In the sixteenth N3- site, N3- is bonded in a 2-coordinate geometry to three Sm3+, one Al3+, and one N3- atom. In the seventeenth N3- site, N3- is bonded in a 1-coordinate geometry to two Sm3+, one Si4+, and one N3- atom. In the eighteenth N3- site, N3- is bonded in a 4-coordinate geometry to three Sm3+, one Si4+, and one N3- atom. In the nineteenth N3- site, N3- is bonded in a distorted trigonal pyramidal geometry to three Sm3+ and one Si4+ atom. In the twentieth N3- site, N3- is bonded in a distorted tetrahedral geometry to three Sm3+ and one Si4+ atom. In the twenty-first N3- site, N3- is bonded in a 2-coordinate geometry to two Sm3+ and two Si4+ atoms. There are twenty-one inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Sm3+ and one Al3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Sm3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Sm3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Sm3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Sm3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Sm3+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sm3+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+ and two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a 3-coordinate geometry to one Sm3+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1998

Nerve-responsive troponin I slow promoter does not respond to unloading

We examined the regulation of the troponin I slow (TnIs) promoter during skeletal muscle unloading-induced protein isoform transition, by using a transgenic mouse line harboring the -4,200 to +12 base pairs region of the human TnIs promoter. Eighteen female transgenic mice ( approximately 30 g body mass) were randomly divided into two groups: weight-bearing (WB) controls (n = 9) and hindlimb unloaded (HU; n = 9). The HU mice were tail suspended for 7 days. Body mass was unchanged in the WB group but was reduced (-6%; P < 0.05) after the HU treatment. Absolute soleus muscle mass (-25%) and soleus mass relative to body mass (-16%) were both lower (P < 0.05) in the HU group compared with the WB mice. Northern blot analyses indicate that 7 days of HU result in a 64% decrease (P < 0.05) in the abundance of endogenous TnIs mRNA (microg/mg muscle) in the mouse soleus. Furthermore, there is a trend for the abundance of the fast troponin I mRNA to be increased (+34%). Analysis of transgenic chloramphenicol acetyltransferase activity in the soleus muscle revealed no difference (P > 0.05) between WB and HU groups. We conclude that additional elements are necessary for the TnIs gene to respond to an unloading-induced, slow-to-fast isoform transition stimulus.

Non-NASA Center↗
NASA NTRS2015

Petrology and Cosmochemistry of a Suite of R Chondrites

Chondrites are among the most primitive surviving materials from the early solar system. They are divided into groups based on chemical types defined by mineralogy, bulk composition, and oxygen isotope compositions. Chondrites range in petrographic grade from type 1 to type 7. Type 3 chondrites are the most primitive and are little changed from the nebular solids accreted to form asteroids. They are composed of chondrules, fine-grained matrix, metal and sulfide, plus or minus Ca-Al-rich inclusions. With increasing aqueous alteration at low temperatures, members of some chondrite classes transformed from type 3 towards type 1. With increasing thermal metamorphism and low fluid content, members of other classes changed from type 3 towards type 7. Rumuruti (R) chondrites are a rare group (0.1% of falls) similar to ordinary chondrites in some properties but different in others. They are characterized by low chondrule/matrix modal abundance ratios, high oxidation state, small mean chondrule size, abundant sulfides and low metal contents. R chondrites vary in petrologic type from 3 to 6. They are important objects to study because some of them have undergone metamorphism at high temperatures in the presence of aqueous fluids. In contrast, CM and CI chondrites were heated to low temperatures in the presence of aqueous fluids leading to alteration; they contain low-T hydrous phases (phyllosilicates) and little or no remaining metal. Ordinary chondrites were heated to high temperatures in a low-fluid environment resulting in anhydrous metamorphic rocks. R6 chondrites are highly metamorphosed and some contain the high-T hydrous phases mica and amphibole. R chondrites are thus unique and give us an opportunity to examine whether there are compositional effects caused by high-T, highfluid metamorphism of nebular materials.

Torrano, Z. A.↗
DOE OSTI2020

Materials Data on Na4GeH28(Se2O7)2 by Materials Project

(Na2(H2O)7)2GeSe4 crystallizes in the monoclinic C2 space group. The structure is two-dimensional and consists of two GeSe4 clusters and one Na2(H2O)7 sheet oriented in the (0, 0, 1) direction. In each GeSe4 cluster, Ge4+ is bonded in a tetrahedral geometry to four Se2- atoms. There are two shorter (2.38 Å) and two longer (2.40 Å) Ge–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted single-bond geometry to one Ge4+ atom. In the second Se2- site, Se2- is bonded in a single-bond geometry to one Ge4+ atom. In the Na2(H2O)7 sheet, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of corner, edge, and face-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Na–O bond distances ranging from 2.38–2.45 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of corner and face-sharing NaO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Na–O bond distances ranging from 2.41–2.48 Å. There are fourteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

1,3-Dimethyl-2,3-dihydrobenzo[ d ]imidazoles, 1H , and 1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[ d ]imidazoles, 1 2 , are of interest as n-dopants for organic electron-transport materials. Salts of 2-(4-(dimethylamino)phenyl)-4,7-dimethoxy-, 2-cyclohexyl-4,7-dimethoxy-, and 2-(5-(dimethylamino)thiophen-2-yl)benzo[ d ]imidazolium ( 1g–i + , respectively) have been synthesized and reduced with NaBH 4 to 1gH , 1hH , and 1iH , and with Na:Hg to 1g 2 and 1h 2 . Their electrochemistry and reactivity were compared to those derived from 2-(4-(dimethylamino)phenyl)- ( 1b + ) and 2-cyclohexylbenzo[ d ]imidazolium ( 1e + ) salts. E ( 1 + / 1 • ) values for 2-aryl species are less reducing than for 2-alkyl analogues, i.e., the radicals are stabilized more by aryl groups than the cations, while 4,7-dimethoxy substitution leads to more reducing E ( 1 + / 1 • ) values, as well as cathodic shifts in E ( 1 2 •+ / 1 2 ) and E ( 1H •+ / 1H ) values. Both the use of 3,4-dimethoxy and 2-aryl substituents accelerates the reaction of the 1H species with PC 61 BM. Because 2-aryl groups stabilize radicals, 1b 2 and 1g 2 exhibit weaker bonds than 1e 2 and 1h 2 and thus react with 6,13-bis(triisopropylsilylethynyl)pentacene ( VII ) via a “cleavage-first” pathway, while 1e 2 and 1h 2 react only via “electron-transfer-first”. 1h 2 exhibits the most cathodic E ( 1 2 •+ / 1 2 ) value of the dimers considered here and, therefore, reacts more rapidly than any of the other dimers with VII via “electron-transfer-first”. Crystal structures show rather long central C–C bonds for 1b 2 (1.5899(11) and 1.6194(8) Å) and 1h 2 (1.6299(13) Å).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2012

Spaceflight Effects and Molecular Responses in the Mouse Eye: Observations After Shuttle Mission STS-133

Microgravity-induced cephalad fluid shift and radiation exposure are some of the stressors seen in space exploration. Ocular changes leading to visual impairment in astronauts are of occupational health relevance. Therefore, we analyzed the effects of space flight in the eyes of mice. Six mice were assigned to Flight (FLT), Animal enclosure Module (AEM), or vivarium (VIV) group, respectively. Mice were sacrificed at 1, 5 or 7 days after landing from space. One eye was used for histological and immunohistoche-mistry analysis and the other eye for gene expression profiling. 8-OHdG and caspase-3 immunoreactivity were increased in the retina in FLT samples at return(R+1) compared to AEM/VIV groups, and decreased at day 7 (R+7). beta-amyloid was seen in the nerve fibers at the post-laminar region of the optic nerve in the flight samples (R+7). In addition, oxidative and cellular stress response genes were upregulated in the retina of FLT samples upon landing, and decreased by R+7. According to the results, a reversible molecular damage may occur in the retina of mice exposed to spaceflight followed by protective cellular response.

Prospero-Ponce, Claudia↗
DOE OSTI2024

Magnetic properties of the quasi-XY Shastry-Sutherland magnet ER 2 Be 2 SiO 7

Polycrystalline and single-crystal samples of the insulating Shastry-Sutherland compound Er 2 ⁢Be 2 ⁢SiO 7 were synthesized via a solid-state reaction and the floating zone method, respectively. The crystal structure, Er single-ion anisotropy, zero-field magnetic ground state, and magnetic phase diagrams along high-symmetry crystallographic directions were investigated with bulk measurement techniques, x-ray and neutron diffraction, and neutron spectroscopy. Here, we establish that Er 2 ⁢Be 2 ⁢SiO 7 crystallizes in a tetragonal space group with planes of orthogonal Er dimers and a strong preference for the Er moments to lie in the local plane perpendicular to each dimer bond. We also find that this system has a noncollinear ordered ground state in zero field with a transition temperature of 0.841 K consisting of antiferromagnetic dimers and in-plane moments. Finally, we mapped out the H-T phase diagrams for Er 2 ⁢Be 2 ⁢SiO 7 along the directions H ∥ [001], [100], and [110]. While an increasing in-plane field simply induces a phase transition to a field-polarized phase, we identify three metamagnetic transitions in the H ∥ [001] case. Single-crystal neutron diffraction results reveal that the H ∥ [001] phase diagram can be explained predominantly by the expected field-induced behavior of classical, anisotropic moments, although the microscopic origin of one phase requires further investigation.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Hydrolysis of Small Oxo/Hydroxo Molecules Containing High Oxidation State Actinides (Th, Pa, U, Np, Pu): A Computational Study

The energetics of hydrolysis reactions for high oxidation states of oxo/hydroxo monomeric actinide species (Th IV O 2 , Pa IV O 2 , U IV O 2 , Pa V O 2 (OH), U V O 2 (OH), U VI O 3 , Np VI O 3 , Np VII O 3 (OH), and Pu VII O 3 (OH)) were calculated at the CCSD(T) level. The first step is the formation of a Lewis acid/base adduct with H 2 O (hydration), followed by a proton transfer to form a dihydroxide molecule (hydrolysis); this process is repeated until all oxo groups are hydrolyzed. The physisorption (hydration) for each H 2 O addition was predicted to be exothermic, ca. -20 kcal/mol. The hydrolysis products are preferred energetically over the hydration products for the +IV and +V oxidation states. The compounds with An VI are a turning point in terms of favoring hydration over hydrolysis. For An VII O 3 (OH), hydration products are preferred, and only two waters can bind; the complete hydrolysis process is now endothermic, and the oxidation state for the An in An(OH) 7 is +VI with two OH groups each having one-half an electron. The natural bond order charges and the reaction energies provide insights into the nature of the hydrolysis/hydration processes. The actinide charges and bond ionicity generally decrease across the period. Here, the ionic character decreases as the oxidation state and coordination number increase so that covalency increases moving to the right in the actinide period.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2016

Analysis of Retinal Vascular Branching in Human Subjects Undergoing 70-Day Head-Down Tilt by NASAs VESGEN Software

Significant risks for visual impairment were discovered recently in astronauts following spaceflight, especially after long-duration missions. We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal vasculature that precede visual and other ocular impairments. We therefore are analyzing retinal vessels in healthy subjects before and after head-down tilt (HDT), a ground-based microgravity analog with NASA's VESsel GENeration Analysis (VESGEN) software. Methods. Spectralis® infrared (IR) fundus images were collected from both eyes of 6 subjects before and after 70 days of bed rest at 6 degree HDT (NASA Campaign 11). For our retrospective study, branching patterns in arterial and venous trees are mapped by VESGEN into vessel branching generations (Gx) that are quantified by parameters such as densities of vessel length (Lv), area (Av), number (Nv) and fractal dimension (Df) as described previously for diabetic retinopathy (IOVS 51(1):498). Results are further assigned by VESGEN into groups of large (G1-3), medium (G4-6) and small (G≥7) vessels. Results. All subjects remained asymptomatic throughout duration of HDT. To date, we have analyzed one IR image from each of the 12 eyes. Interestingly, two groups of the masked study population identified by VESGEN are distinguished by the presence or absence of small veins (G≥7). For example, L≥7 and Av≥7 are 2.7+/-1.3 E-4 px/px2 and 7.2+/-3.6 E-4 px2/px2 in 6 retinas, but 0 in the other 6 retinas. Nonetheless, the space-filling properties of the entire venous trees were remarkably uniform by all parameters, such as Df = 1.56+/-0.02 for 6 retinas with G≥7 and 1.55+/-0.02 for retinas without G≥7. No small arteries (G≥7) were detected. Conclusions. For our preliminary masked analysis, two groups of venous trees with and without small veins (G≥7) were clearly revealed by VESGEN. Upon completing all images and unmasking the subject status of before and after HDT, we will determine whether differences in the presence or absence of small veins are important correlates, and perhaps reliable predictors, of other ocular and physiological adaptations to prolonged head-down tilt and microgravity. Clinical methods for examining adaptive microvascular remodeling in the retina to microgravity space flight are not currently established.

Fractal↗
NASA NTRS1996

Insect Development in Altered Gravitational Environment

When tobacco hornworm (Manduca sexta) larvae burrow underground (25-30 cm) to pupate, they reorient themselves to a relatively horizontal position indicating an ability to sense gravity. To evaluate their sensitivity to gravitational environment during metamorphosis, Manduca (pharate adults) were placed in a vertical (head-up) position. Distinct morphological changes, each one reflecting ensuing phases, were used to follow adult development. Five days after pupation, the vertical group showed accelerated (P less than 0.05) development and were nearly 4 phases ahead (P less than 0.0001) after 10 days. Differences in development in the vertical group were characterized further by increased (7-48%) hemolymph concentrations of 13 amino acids, but a decrease in cys and pro and no change in arg, his, met and val (trp, undetectable). Decreased (36%) turnover of injected H-3 - phenylalanine suggested slower utilization of amino acids contributed, at least partly, to the increased concentrations. Vertically-oriented Manduca also exhibited a greater (20 %, P less than 0.001) protein content in their flight muscles near the end of development. Analysis of hemolymph sugar levels showed a redistribution of sugars from the monosaccharide glucose to the disaccharide trehalose. Since injection of 20-hydroxyecdysone decreased (49%) turnover of H-3- phenylalanine in pharate adults and since ecdysteroids are known to increase flight muscle size and control adult development, these results are consistent with our measuring a greater (+80%, P less than 0.05) ecdysteroid titer in the vertically-oriented insects. These results suggest that gravity environment influences ecdysone output by the pharate adult. When we evaluated hemolymph flow in the head-up and control positions, we found that injected C-14-inulin was distributed somewhat more rapidly in the head-up group irrespective of the sight of injection (head or abdomen) likely because in the head-up position flow of the hemolymph is facilitated throughout the animal. Other experiments showed that an intact prothoracic gland is needed for the response. Hence vertical, head-up orientation affects release of ecdysone from the prothoracic gland.

Tischler, Marc E.↗
DOE OSTI2022

The eROSITA Final Equatorial-Depth Survey (eFEDS)

In 2019, the eROSITA telescope on board the Russian-German satellite Spectrum-Roentgen-Gamma (SRG) began to perform a deep all-sky X-ray survey with the aim of identifying ~100 000 clusters and groups over the course of four years. As part of its performance verification phase, a ~140 deg 2 survey, called eROSITA Final Equatorial-Depth Survey (eFEDS), was performed. With a depth typical of the all-sky survey after four years, it allows tests of tools and methods as well as improved predictions for the all-sky survey. As part of this effort, a catalog of 542 X-ray selected galaxy group and cluster candidates was compiled. Here, in this paper, we present the optical follow-up, with the aim of providing redshifts and cluster confirmation for the full sample. Furthermore, we aim to provide additional information on the dynamical state, richness, and optical center of the clusters. Finally, we aim to evaluate the impact of optical cluster confirmation on the purity and completeness of the X-ray selected sample. We used optical imaging data from the Hyper Suprime-Cam Subaru Strategic Program and from the Legacy Survey to identify optical counterparts to the X-ray detected cluster candidates. We make use of the multi-component matched filter cluster confirmation tool (MCMF), as well as of the optical cluster finder CAMIRA to derive cluster redshifts and richnesses. MCMF provided the probabilities with which an optical structure would be a chance superposition with the X-ray candidate. These probabilities were used to identify the best optical counterpart as well as to confirm an X-ray candidate as a cluster. The impact of this confirmation process on catalog purity and completeness was estimated using optical to X-ray scaling relations as well as simulations. The resulting catalog was furthermore matched with public group and cluster catalogs. Optical estimators of the cluster dynamical state were constructed based on density maps of the red-sequence galaxies at the cluster redshift. By providing redshift estimates for all 542 candidates, we construct an optically confirmed sample of 477 clusters and groups with a residual contamination of 6%. Of these, 470 (98.5%) are confirmed using MCMF, and 7 systems are added through cross-matching with spectroscopic group catalogs. Using observable-to-observable scaling and the applied confirmation threshold, we predict that 8 ± 2 real systems have been excluded with the MCMF cut required to build this low-contamination sample. This number agrees well with the 7 systems found through cross-matching that were not confirmed with MCMF. The predicted redshift and mass distribution of this catalog agree well with simulations. Thus, we expect that these 477 systems include >99% of all true clusters in the candidate list. Using an MCMF-independent method, we confirm that the catalog contamination of the confirmed subsample is 6 ± 3%. Application of the same method to the full candidate list yields 17 ± 3%, consistent with estimates coming from the fraction of confirmed systems of ~17% and with expectations from simulations of ~20%. We also present a sample of merging cluster candidates based on the derived estimators of the cluster dynamical state.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Materials Data on K5In3(SiO3)7 by Materials Project

K5In3(SiO3)7 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are five inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.72–3.11 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.27 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.37 Å. In the fourth K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.45 Å. In the fifth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.25 Å. There are three inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to five O2- atoms to form InO5 trigonal bipyramids that share corners with five SiO4 tetrahedra. There are a spread of In–O bond distances ranging from 2.12–2.15 Å. In the second In3+ site, In3+ is bonded to six O2- atoms to form InO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one InO6 octahedra. There are a spread of In–O bond distances ranging from 2.11–2.30 Å. In the third In3+ site, In3+ is bonded to six O2- atoms to form InO6 octahedra that share corners with six SiO4 tetrahedra and a faceface with one InO6 octahedra. There are a spread of In–O bond distances ranging from 2.12–2.37 Å. There are seven inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two InO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one InO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 41–57°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one InO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one InO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three InO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–55°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one InO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one InO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent InO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one InO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one InO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 52°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two InO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one InO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are twenty-one inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two In3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two In3+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two In3+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one In3+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one In3+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Re6(SCl)7 by Materials Project

Cs3Re6(SCl)7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to two S2- and five Cl1- atoms. There are one shorter (3.59 Å) and one longer (3.79 Å) Cs–S bond lengths. There are a spread of Cs–Cl bond distances ranging from 3.60–3.97 Å. In the second Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to one S2- and six Cl1- atoms. The Cs–S bond length is 3.78 Å. There are a spread of Cs–Cl bond distances ranging from 3.56–3.96 Å. In the third Cs1+ site, Cs1+ is bonded in a 10-coordinate geometry to five S2- and five Cl1- atoms. There are a spread of Cs–S bond distances ranging from 3.69–4.16 Å. There are a spread of Cs–Cl bond distances ranging from 3.61–4.10 Å. There are six inequivalent Re3+ sites. In the first Re3+ site, Re3+ is bonded to four S2- and one Cl1- atom to form edge-sharing ReS4Cl square pyramids. There are a spread of Re–S bond distances ranging from 2.41–2.43 Å. The Re–Cl bond length is 2.46 Å. In the second Re3+ site, Re3+ is bonded to three S2- and two Cl1- atoms to form edge-sharing ReS3Cl2 square pyramids. There are one shorter (2.38 Å) and two longer (2.42 Å) Re–S bond lengths. There are one shorter (2.45 Å) and one longer (2.53 Å) Re–Cl bond lengths. In the third Re3+ site, Re3+ is bonded to four S2- and one Cl1- atom to form edge-sharing ReS4Cl square pyramids. There are a spread of Re–S bond distances ranging from 2.41–2.43 Å. The Re–Cl bond length is 2.43 Å. In the fourth Re3+ site, Re3+ is bonded to three S2- and two Cl1- atoms to form edge-sharing ReS3Cl2 square pyramids. There are one shorter (2.38 Å) and two longer (2.42 Å) Re–S bond lengths. There are one shorter (2.41 Å) and one longer (2.55 Å) Re–Cl bond lengths. In the fifth Re3+ site, Re3+ is bonded to four S2- and one Cl1- atom to form edge-sharing ReS4Cl square pyramids. There are two shorter (2.42 Å) and two longer (2.43 Å) Re–S bond lengths. The Re–Cl bond length is 2.44 Å. In the sixth Re3+ site, Re3+ is bonded to three S2- and two Cl1- atoms to form edge-sharing ReS3Cl2 square pyramids. There are one shorter (2.37 Å) and two longer (2.42 Å) Re–S bond lengths. There are one shorter (2.41 Å) and one longer (2.56 Å) Re–Cl bond lengths. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three Re3+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Re3+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to one Cs1+ and three Re3+ atoms. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to one Cs1+ and three Re3+ atoms. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to two Cs1+ and three Re3+ atoms. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to two Cs1+ and three Re3+ atoms. In the seventh S2- site, S2- is bonded in a 4-coordinate geometry to two Cs1+ and three Re3+ atoms. There are seven inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 1-coordinate geometry to three Cs1+ and one Re3+ atom. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to three Cs1+ and one Re3+ atom. In the third Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two Cs1+ and one Re3+ atom. In the fourth Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two Cs1+ and one Re3+ atom. In the fifth Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two Cs1+ and one Re3+ atom. In the sixth Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two Cs1+ and one Re3+ atom. In the seventh Cl1- site, Cl1- is bonded in a 4-coordinate geometry to two Cs1+ and three Re3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Impact of Mg Substitution on the Structure, Stability, and Properties of the Na 2 Fe 2 F 7 Weberite Cathode

Of the few weberite-type Na-ion cathodes explored to date, Na 2 Fe 2 F 7 exhibits the best performance, with capacities up to 184 mAh/g and energy densities up to 550 Wh/kg reported for this material. However, the development of robust structure–property relationships for this material is complicated by its tendency to form as a mixture of metastable polymorphs, and transform to a lower-energy Na y FeF 3 perovskite compound during electrochemical cycling. Our first-principles-guided exploration of Fe-based weberite solid solutions with redox-inactive Mg 2+ and Al 3+ predicts an enhanced thermodynamic stability of Na 2 Mg x Fe 2–x F 7 as the Mg content is increased, and the x = 0.125 composition is selected for further exploration. We demonstrate that the monoclinic polymorph (space group C2/c) of Na 2 Fe 2 F 7 (Mg0) and of a new Mg-substituted weberite composition, Na 2 Mg 0.125 Fe 1.875 F 7 (Mg0.125), can be isolated using an optimized synthesis protocol. The impact of Mg substitution on the stability of the weberite phase during electrochemical cycling, and on the extent and rate of Na (de)intercalation, is examined. Irrespective of the Mg content, we find that the weberite phase is retained when cycling over a narrow voltage window (2.8–4.0 V vs Na/Na+). Over a wider voltage range (1.9–4.0 V), Mg0 shows steady capacity fade due to its transformation to the NayFeF3 perovskite phase, while Mg0.125 displays more reversible cycling and a reduced phase transformation. Yet, Mg incorporation also leads to kinetically limited Na extraction and a reduced overall capacity. These findings highlight the need for the continued compositional optimization of weberite cathodes to improve their structural stability while maximizing their energy density.

25 ENERGY STORAGE↗