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DOE OSTI2020

Materials Data on Be(B3H7)2 by Materials Project

BeB5H13BH is alpha carbon monoxide-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four boranediylradical molecules and four BeB5H13 clusters. In each BeB5H13 cluster, Be2+ is bonded in a 4-coordinate geometry to four H+0.71+ atoms. There are a spread of Be–H bond distances ranging from 1.53–1.59 Å. There are five inequivalent B2- sites. In the first B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.34 Å. In the second B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.19–1.35 Å. In the third B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.19–1.35 Å. In the fourth B2- site, B2- is bonded in a distorted trigonal non-coplanar geometry to three H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.34 Å. In the fifth B2- site, B2- is bonded in a tetrahedral geometry to four H+0.71+ atoms. There are a spread of B–H bond distances ranging from 1.20–1.26 Å. There are thirteen inequivalent H+0.71+ sites. In the first H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the second H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the third H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the fourth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the fifth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the sixth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the seventh H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the eighth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to one Be2+ and one B2- atom. In the ninth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom. In the tenth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the eleventh H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the twelfth H+0.71+ site, H+0.71+ is bonded in an L-shaped geometry to two B2- atoms. In the thirteenth H+0.71+ site, H+0.71+ is bonded in a single-bond geometry to one B2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Se2NCl5 by Materials Project

N2(Se2Cl5)2 is alpha carbon monoxide-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight ammonia molecules and eight Se2Cl5 clusters. In four of the Se2Cl5 clusters, there are two inequivalent Se1+ sites. In the first Se1+ site, Se1+ is bonded in a 3-coordinate geometry to three Cl1- atoms. There are a spread of Se–Cl bond distances ranging from 2.22–2.77 Å. In the second Se1+ site, Se1+ is bonded in a distorted T-shaped geometry to three Cl1- atoms. There are a spread of Se–Cl bond distances ranging from 2.24–2.70 Å. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the fifth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Se1+ atoms. In four of the Se2Cl5 clusters, there are two inequivalent Se1+ sites. In the first Se1+ site, Se1+ is bonded in a 3-coordinate geometry to three Cl1- atoms. There are a spread of Se–Cl bond distances ranging from 2.22–2.72 Å. In the second Se1+ site, Se1+ is bonded in a distorted T-shaped geometry to three Cl1- atoms. There are a spread of Se–Cl bond distances ranging from 2.22–2.71 Å. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom. In the fourth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two Se1+ atoms. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Se1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb2SbBr6 by Materials Project

(Rb)2SbBr6 is alpha bismuth trifluoride-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is zero-dimensional and consists of sixteen rubidium molecules and eight SbBr6 clusters. In each SbBr6 cluster, Sb2- is bonded in an octahedral geometry to six Br atoms. There are two shorter (2.67 Å) and four longer (2.68 Å) Sb–Br bond lengths. There are two inequivalent Br sites. In the first Br site, Br is bonded in a single-bond geometry to one Sb2- atom. In the second Br site, Br is bonded in a single-bond geometry to one Sb2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na3TlH24(ClO2)6 by Materials Project

(Na3H19O11)2(TlCl6)2(H2)4H2O2 is alpha Pu-derived structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two hydrogen molecules, one water molecule, one Na3H19O11 cluster, and one TlCl6 cluster. In the Na3H19O11 cluster, there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.43 Å. In the second Na1+ site, Na1+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.56 Å. In the third Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.43–2.58 Å. There are nineteen 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 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 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 0.99 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the tenth 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 eleventh 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 twelfth 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 thirteenth 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 fourteenth 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 fifteenth 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 sixteenth 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 seventeenth 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 eighteenth 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 nineteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted 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 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 one Na1+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a single-bond geometry to one Na1+ and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+ and one H1+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+ and one H1+ atom. In the TlCl6 cluster, Tl3+ is bonded in an octahedral geometry to six Cl1- atoms. There are a spread of Tl–Cl bond distances ranging from 2.58–2.71 Å. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom. In the fifth Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom. In the sixth Cl1- site, Cl1- is bonded in a single-bond geometry to one Tl3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn2H18Cl4O9 by Materials Project

Zn(H2O)6ZnCl4(H2O)3 is alpha Pu-derived structured and crystallizes in the orthorhombic P2_12_12_1 space group. The structure is zero-dimensional and consists of twelve water molecules, four ZnCl4 clusters, and four zinc hexahydrate molecules. In each ZnCl4 cluster, Zn2+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are a spread of Zn–Cl bond distances ranging from 2.28–2.31 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Zn2+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Zn2+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Zn2+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Zn2+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1994

Radial velocities of very low mass stars and candidate brown dwarf members of the Hyades and Pleiades

We have determined H alpha equivalent widths and radial velocities with 1 sigma accuracies of approximately 5 km s(exp -1) for approximately 20 candidate very low mass members of the Hyades and Pleiades clusters. The radial velocities for the Hyades sample suggest that nearly all of these stars are indeed highly probable members of the Hyades. The faintest stars in the Hyades sample have masses of order 0.1 solar mass. We also obtained radial velocities for four candidate very low mass members of the Pleiades and two objects that are candidate BD Pleiads. All of these stars have apparent V magnitudes fainter than the Hyades stars we observed, and the resultant radial velocity accuracy is worse. We believe that the three brighter stars are indeed likely very low mass stellar members of the Pleiades, whereas the status of the two brown dwarf candidates is uncertain. The Hyades stars we have observed and the three Pleiades very low mass stars are the lowest mass members of any open cluster whose membership has been confirmed by radial velocities and whose chromospheric activity has been measured. We see no change in chromospheric activity at the boundary where stars are expected to become fully convective (M approximately equals 0.3 solar mass) in either cluster. In the Pleiades, however, there may be a decrease in chromospheric activity for stars with (V-I)(sub K) greater than 3.5 (M less than or equal to 0.1 solar mass).

Stauffer, John R.↗
NASA NTRS2007

Radio Sources Toward Galaxy Clusters at 30 GHz

Extra-galactic radio sources are a significant contaminant in cosmic microwave background and Sunyaev-Zeldovich effect experiments. Deep interferometric observations with the BIMA and OVRO arrays are used to characterize the spatial, spectral, and flux distributions of radio sources toward massive galaxy clusters at 28.5 GHz. We compute counts of mJy source fluxes from 89 fields centered on known massive galaxy clusters and 8 non-cluster fields. We find that source counts in the inner regions of the cluster fields (within 0.5 arcmin of the cluster center) are a factor of 8.9 (+4.2 to -3.8) times higher than counts in the outer regions of the cluster fields (radius greater than 0.5 arcmin). Counts in the outer regions of the cluster fields are in turn a factor of 3.3 (+4.1 -1.8) greater than those in the noncluster fields. Counts in the non-cluster fields are consistent with extrapolations from the results of other surveys. We compute spectral indices of mJy sources in cluster fields between 1.4 and 28.5 GHz and find a mean spectral index of al[ja = 0.66 with an rms dispersion of 0.36, where flux S varies as upsilon(sup -alpha). The distribution is skewed, with a median spectral index of 0.72 and 25th and 75th percentiles of 0.51 and 0.92, respectively. This is steeper than the spectral indices of stronger field sources measured by other surveys.

Coble, K.↗
NASA NTRS1994

Globular cluster photometry with the Hubble Space Telescope. 2: U, V, and I measurements of M15

The projected density distribution of resolved stars near the center of M15 is shown to be consistent with either a power-law cusp N(r) approximately r(exp alpha), with alpha approximately -0.85 +/- 0.2, or with a King model with a core of radius approximately less than 2 sec. The inferred slope is in agreement with the theoretical value, alpha = -0.75, calculated by Bahcall and Wolf for the distribution of equal-mass stars surrounding a massive black hole and is also consistent with the radial profile expected from core collapse without a central black hole. The object AC 214 is a candidate for the central density cusp. Analysis of Monte Carlo simulations of the diffuse light indicates that, using current analysis techniques and available data, the residual light is not a reliable indicator of the true density distribution. This is contrary to earlier work. Photometric measurements in V and I of more than 5 x 10(exp 3) stars (and in U, V, and I of approximately greater than 1500 stars) are used to construct color-magnitude diagrams in the central 1 min of M15. Fourteen blue straggler candidates are identified in the inner 20 sec. The central color gradient noticed by previous researchers is caused by a central depletion of bright red giant stars rather than an excess of blue stragglers or blue horizontal branch stars.

Yanny, Brian↗
DOE OSTI2020

Materials Data on UH12(NO7)2 by Materials Project

UH4(NO5)2(H2O)4 is alpha Pu-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is zero-dimensional and consists of sixteen water molecules and four UH4(NO5)2 clusters. In each UH4(NO5)2 cluster, U6+ is bonded in a distorted linear geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 1.80–2.57 Å. There are two inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.24 Å) and two longer (1.28 Å) N–O bond length. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.25 Å) and two longer (1.27 Å) N–O bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one U6+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one U6+ and one N5+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one U6+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one U6+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one U6+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a single-bond geometry to one N5+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ir(N3O4)3 by Materials Project

(Ir(NO2)6)2(N2)3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is zero-dimensional and consists of twelve ammonia molecules and four Ir(NO2)6 clusters. In each Ir(NO2)6 cluster, Ir3+ is bonded in a cuboctahedral geometry to twelve equivalent O2- atoms. All Ir–O bond lengths are 2.26 Å. N+2.33+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. All N–O bond lengths are 1.95 Å. O2- is bonded in a 3-coordinate geometry to one Ir3+ and two equivalent N+2.33+ atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1982

Observations of NGC 604 over six decades in frequency

Maps in the near-infrared, H-alpha and radio continuum have been obtained of NGC 604, the brightest H II region complex in M33, as well as a measurement of the UV spectrum of the ionizing star cluster. The data show that NGC 604 consists of about ten components of typical size 10 pc, embedded in a much larger envelope with dimensions of 225 pc. At least one component is optically almost completely obscured; it is located close to another object that is only detected in the near-infrared and whose nature is uncertain.

Israel, F. P.↗
DOE OSTI2020

Materials Data on ReN(OF2)3 by Materials Project

ReOF6NO2 is alpha Pu-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight hydroxylamine, n-hydroxy- molecules and eight ReOF6 clusters. In each ReOF6 cluster, Re7+ is bonded in a pentagonal bipyramidal geometry to one O2- and six F1- atoms. The Re–O bond length is 1.71 Å. There are a spread of Re–F bond distances ranging from 1.92–1.97 Å. O2- is bonded in a single-bond geometry to one Re7+ atom. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Re7+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Re7+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to one Re7+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Re7+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Re7+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Re7+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SiH18C2N8(OF3)2 by Materials Project

(CN4H7)2SiF6(H2O)2 is alpha Pu-derived structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two aminoguanidinium molecules, two water molecules, and one SiF6 cluster. In the SiF6 cluster, Si4+ is bonded in an octahedral geometry to six F1- atoms. There is four shorter (1.72 Å) and two longer (1.73 Å) Si–F bond length. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Si4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Si4+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiSi4H27(C3O)3 by Materials Project

LiSi3H27(C3O)3Si is alpha carbon monoxide-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four silicon molecules and four LiSi3H27(C3O)3 clusters. In each LiSi3H27(C3O)3 cluster, Li1+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.99 Å) and two longer (2.00 Å) Li–O bond length. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two C4- and one O2- atom. Both Si–C bond lengths are 1.89 Å. The Si–O bond length is 1.73 Å. In the second Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two C4- and one O2- atom. Both Si–C bond lengths are 1.89 Å. The Si–O bond length is 1.73 Å. In the third Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two C4- and one O2- atom. Both Si–C bond lengths are 1.89 Å. The Si–O bond length is 1.73 Å. There are nine inequivalent C4- sites. In the first C4- site, C4- is bonded in a tetrahedral geometry to three H+0.93+ and one O2- atom. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.44 Å. In the second C4- site, C4- is bonded in a tetrahedral geometry to three H+0.93+ and one O2- atom. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.44 Å. In the third C4- site, C4- is bonded in a tetrahedral geometry to three H+0.93+ and one O2- atom. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.43 Å. In the fourth C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. In the fifth C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. In the sixth C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. In the seventh C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. In the eighth C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. In the ninth C4- site, C4- is bonded to one Si4+ and three H+0.93+ atoms to form corner-sharing CSiH3 tetrahedra. All C–H bond lengths are 1.10 Å. There are twenty-seven inequivalent H+0.93+ sites. In the first H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the second H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the third H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the fourth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the fifth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the sixth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the seventh H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the eighth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the ninth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the tenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the eleventh H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twelfth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the thirteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the fourteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the fifteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the sixteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the seventeenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the eighteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the nineteenth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twentieth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-first H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-second H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-third H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-fourth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-fifth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-sixth H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. In the twenty-seventh H+0.93+ site, H+0.93+ is bonded in a single-bond geometry to one C4- atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Si4+, and one C4- atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Si4+, and one C4- atom. In the third O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Si4+, and one C4- atom.

36 MATERIALS SCIENCE↗
NASA NTRS1987

Discrete X-ray sources and the X-ray background

Since the discovery of a highly uniform X-ray background (XRB) in the 2 to 10 keV range, its nature is not yet fully explained. It appears clear from the results of Einstein medium and deep surveys that at least 50% of the XRB is due to individual extragalactic sources when their contribution is integrated to Z = 3. This includes contribution from Quasi Stellar Objects (QSOs), Active Galactic Nuclei (AGNs), galaxies, and clusters of galaxies. The average spectrum of each of the individual contributing sources is softer than that of the observed XRB. Therefore, the remaining contribution must have a rather hard spectrum of alpha nearly equal to 0.0 to 0.2. It is unlikely that this spectrum can be produced by diffuse processes. Therefore, the remainder of the XRB must be due to individual sources with the appropriate spectrum. This requires either that the spectrum of the already identified sources changes at early epochs or a new class of objects. Advanced X-ray Astrophysics Facility (AXAF) observations will extend survey sensitivity to limiting fluxes of order of 3 x 10 to the minus 16 erg/sq cm/s, some 50 times fainter than any previous survey. There will be sufficient sensitivity and angular resolution to permit identification and study of these objects.

Giacconi, Riccardo↗
DOE OSTI2020

Materials Data on SbI3Cl8 by Materials Project

Sb(ICl4)2I is alpha Niobium phosphide-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one hydriodic acid molecule and one Sb(ICl4)2 cluster. In the Sb(ICl4)2 cluster, Sb5+ is bonded in an octahedral geometry to six Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.38–2.51 Å. I1+ is bonded in a linear geometry to two Cl1- atoms. There are one shorter (2.39 Å) and one longer (2.82 Å) I–Cl bond lengths. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one I1+ atom. In the third Cl1- site, Cl1- is bonded in a distorted bent 120 degrees geometry to one Sb5+ and one I1+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2002

ATCA Detects Cometary-Shaped Objects In the Giant H II Region

Three protoplanetary disks in the giant H II region NGC 3603, originally found by HST (Hubble Space Telescope) + VLT (Very Large Telescope), have been detected with the ATCA (Australia Telescope Compact Array) at 3 and 6 cm. All three ProPlyDs (protoplanetary disks) are clearly resolved, showing a head-tail extent of approx. 4 inches. Proplyd 3 shows the most pronounced head-tail structure with a 3 cm flux density ratio between head and tail of about 10:1. The tail is very well defined and at least 2 inches long, pointing away from the central star cluster. Unfortunately, ProPlyD 3 is rather faint in the low-sensitivity HST broad band image shown by Brandner et al.; it is located outside the region of their high sensitivity HST H(alpha) image.

Mucke, A.↗
NASA NTRS1980

Electron-temperature dependence of dissociative recombination of electrons with CO(+)-(CO)n-series ions

A microwave afterglow mass spectrometer apparatus is used to determine the dependence on electron temperature T sub e of the recombination coefficients alpha sub n of the dimer and trimer ions of the series CO+.(CO) sub n. It is found that alpha sub 1 = (1.3 + or - 0.3)x 0.000001 (T sub e(K)/300) to the -0.34; and alpha sub 2 = (1.9 + or - 0.4)x 0.000001 (T sub e(K)/300) to the -0.33 cu cm/sec. These dependences on T sub e are quite different from those obtained previously for polar-cluster ions of the hydronium and ammonium series but are similar to that for simple diatomic ions.

Whitaker, M.↗