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All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

T wave alternans threshold late after repair of tetralogy of Fallot

INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) is a marker of increased risk for malignant ventricular arrhythmia. There is a significant risk of arrhythmia and sudden death after repair of congenital heart disease. The aim of this study was to determine the prevalence and characteristics of TWA after repair of tetralogy of Fallot (TOF). METHODS AND RESULTS: TWA was evaluated during bicycle exercise in 49 subjects who had consecutively undergone transatrial-transpulmonary repair. Median values for age, age at repair, and follow-up duration were 14.9 years (11.5-20.8), 1.6 years (0.2-4.9), and 11.6 years (9.4-17.2), respectively. All patients were in New York Heart Association functional class I and were asymptomatic. Median QRS duration was 120 msec (80-150). Sustained TWA was detected in 7 (23%) of 31 subjects with adequate tests. In these 7 subjects, median onset heart rate (HR) was 120 (98-155). Median HR threshold as a percentage of predicted maximum HR (220 - age) was 58% (48-77). Sustained TWA prevalence was not significantly different compared with normal subjects (7/31 vs 9/83; P = 0.1). Onset HR in the TOF group was significantly lower [mean (SD) of 122 (20) vs 139 (12), P < 0.05]. In the TOF group with sustained TWA, the TWA occurred in 4 of 7 at <60% predicted maximum HR versus 1 of 9 normal subjects (P < 0.05); 3 of 7 had onset HR <120 versus 0 of 9 normal subjects (P < 0.03). There was no significant difference in age, gender, transannular patch use, restrictive right ventricular physiology, QRS duration, QTc, QT/QRS dispersion, or nonsustained ventricular tachycardia in subjects with or those without sustained TWA. CONCLUSION: The onset HR for sustained TWA is significantly lower after repair of TOF. Further study is required to determine whether this represents an increased risk for arrhythmia in this patient group.

Non-NASA Center↗
NASA NTRSDate not supplied

Multi-Omics Analysis of Mouse Retina Following Low Dose Radiation and/or Hindlimb Unloading

Rodent models have been used as analogs for studying the effects of spaceflight. NASA’s GeneLab provides access to omics datasets generated from spaceflight and ground-based experiments allowing for additional retrospective analysis. We used GeneLab’s GLDS-203, a dataset generated by researchers at Loma Linda University to study the impact of prolonged unloading and/or low-dose radiation on mouse retina. The purpose of this study was to understand the effect of gamma radiation and/or hindlimb unloading on mice retinas through a multi-omics analysis. In the experiment that generated the omics data, mice were irradiated with gamma-ray and/or subjected to hindlimb unloading for 21 days and multi-omics analysis was performed at 7 days, 1 month, or 4 months post exposure. In the current study, for each of the three timepoints, we compared epigenomic profiles for retinas from exposed mice against timepoint-matched controls. We identified a total of 5,271 differentially methylated loci (DML) and 321 differentially methylated regions (DMR; using a sliding window and step size of 500 bp) with methylation difference > 10% and q-value < 0.05 (sliding linear model corrected p-value) across the nine exposure groups. Highest correlation in methylation difference was seen for significant DMLs (q-value < 0.05) across different conditions at same post exposure timepoint (Figure 1).The location of DMLs and DMRs were characterized with respect to CpG islands and shores, putative promoters, gene body, and intergenic regions (Table 1). We analyzed RNA-seq counts and performed gene set enrichment analysis using differential expression results from comparing each exposure group to its timepoint-matched control group. Significant pathways (adjusted p-value <0.05) enriched in all three microgravity-only groups were related to morphogenesis of a branching epithelium, skeletal muscle cell differentiation, and response to fibroblast growth factor. Common processes across all timepoints in the radiation-only groups were retina homeostasis, synaptic vesicle exocytosis-endocytosis, and chemotaxis. In the combination groups, regulation of trans-synaptic signaling, and Rho protein signal transduction were enriched at all three timepoints. Processes related to purine nucleotide metabolism were enriched in all nine exposure groups, with activation at 1 month, and suppression at 7 days and 4 months. A total of 14 genes contained at least one DML and were differentially expressed at adjusted p-value < 0.05, including genes implicated in cataract development (Sipa1l3, Crybb3) and those involved in cytoskeletal organization (Plec, Flnb, Eef1a1). This analysis is part of a larger effort to understand the molecular mechanisms following spaceflight exposures that can help translate effects observed in animal models to human impacts.

Prachi Kothiyal↗
NASA NTRS2000

Hematological and TGF-beta variations after whole-body proton irradiation

The acute effects of proton whole-body irradiation on five bone-marrow-derived cell types and transforming growth factor-beta 1 (TGF-beta 1) were examined and compared to the effects of photons (60Co). C57BL/6 mice were exposed to 3 Gy (0.4 Gy/min) protons at spread-out Bragg peak (SOBP), protons at entry (E), or 60Co and euthanized on days 0.5-17 thereafter. 60Co-irradiated animals had decreased erythrocytes, hemoglobin and hematocrit at 12 hours post-exposure; depression was not noted in proton (SOBP or E)-irradiated groups until day 4. Significantly decreased leukocyte counts were observed at this same time in all irradiated groups, with lymphocyte loss being greater than that of monocytes, and the depression was generally maintained. In contrast, the levels of neutrophils and thrombocytes fluctuated, especially during the first week; significant differences were noted among irradiated groups in neutrophil levels. Plasma TGF-beta 1 was elevated on day 7 in the 60Co, but not proton, irradiated mice. Collectively, the data show that dramatic and persistent changes occurred in all irradiated groups. However, few differences in assay results were seen between animals exposed to protons (SOBP or E) or photons, as well as between the groups irradiated with either of the two regions of the proton Bragg curve.

Non-NASA Center↗
DOE OSTI2023

From Layered Antiferromagnet to 3D Ferromagnet: LiMnBi-to-MnBi Magneto-Structural Transformation

Here, the intermetallic compound LiMnBi was synthesized by the two-step solid-state reaction from the elements. The synthesis temperature of 850 K was selected based on in-situ high-temperature powder X-ray diffraction data. LiMnBi crystalizes in the layered-like PbClF structure type (a = 4.3131(7) Å, c = 7.096(1) Å at 100 K, P4/nmm space group, Z = 2). LiMnBi structure is built of the alternating [MnBi] and Li layers, as determined from single-crystal X-ray diffraction data. Magnetic properties measurements and solid-state 7 Li Nuclear Magnetic Resonance data collected for polycrystalline LiMnBi samples indicate the long-range antiferromagnetic ordering of Mn sublattice at ~340 K, with no superconductivity down to 5 K detected. LiMnBi is air- and water-sensitive. In aerobic conditions, Li can be extracted from LiMnBi structure to form Li 2 O/LiOH and MnBi (NiAs structure type, P6 3 /mmc). The obtained MnBi polymorph was previously reported to be one of the strongest rare-earth-free ferromagnets, yet its bulk synthesis in powder form is cumbersome. The proposed magneto-structural transformation from ternary LiMnBi to ferromagnetic MnBi involves condensation of the MnBi4 tetrahedra upon Li deintercalation and is exclusive to LiMnBi. In contrast, ferromagnetic MnBi cannot be obtained from either isostructural NaMnBi and KMnBi, or from the structurally related CaMn 2 Bi 2 . Such a distinctive transformation in the case of LiMnBi is presumed to be due to its fitting reactivity to yield MnBi and favorable interlayer distance between [MnBi] layers, while the interlayer distance in NaMnBi and KMnBi structural analogs is unfavorably long. The studies of delithiation from the layered-like LiMnBi under different chemical environments indicate that the yield of the MnBi depends on the type of solvent used and the kinetics of the reaction. A slow rate and mild reaction media lead to a high fraction of the MnBi product. The saturation magnetization of the “as-prepared” MnBi is ~50 % of the expected value of 81.3 emu/g. Overall, this study adds a missing member to the family of ternary pnictides and illustrates how soft-chemistry methods can be used to obtain “difficult-to-synthesize” compounds.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on HgTe(HO)7 by Materials Project

HgH5TeO6H2O crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of two water molecules and one HgH5TeO6 ribbon oriented in the (0, 1, 1) direction. In the HgH5TeO6 ribbon, Hg1+ is bonded in a distorted single-bond geometry to one O2- atom. The Hg–O bond length is 2.18 Å. There are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. 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. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are two inequivalent Te6+ sites. In the first Te6+ site, Te6+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Te–O bond distances ranging from 1.93–1.98 Å. In the second Te6+ site, Te6+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Te–O bond distances ranging from 1.90–2.02 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one H1+ and one Te6+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one H1+ and one Te6+ atom. In the third O2- site, O2- is bonded in a distorted water-like geometry to one H1+ and one Te6+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to one Hg1+, one H1+, and one Te6+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one H1+ and one Te6+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one H1+ and one Te6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Li4(BO2)7 by Materials Project

Li4Cs3B7O14 crystallizes in the trigonal P3_121 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of Cs–O bond distances ranging from 2.98–3.67 Å. In the second Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 3.14–3.44 Å. There are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.43 Å. In the second Li1+ site, Li1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.89–2.11 Å. There are four inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.47–1.51 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.34 Å) and two longer (1.41 Å) B–O bond length. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.34–1.44 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.34–1.42 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two Cs1+, two equivalent Li1+, and one B3+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to three Cs1+ and two B3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+, one Li1+, and two B3+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Cs1+, two Li1+, and one B3+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Li1+ and two equivalent B3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Cs1+, two equivalent Li1+, and one B3+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Cs1+, two Li1+, and two B3+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to three equivalent Cs1+ and two B3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na4MgV10(H11O13)4 by Materials Project

(Na2V5(H2O3)7)2Mg(H2O)6(H2O)2O2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one magnesium;hexahydrate molecule; two water molecules; two water molecules; and one Na2V5(H2O3)7 sheet oriented in the (1, -1, 0) direction. In the Na2V5(H2O3)7 sheet, there are three inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.36–2.68 Å. In the second Na site, Na is bonded to six O atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.37–2.45 Å. In the third Na site, Na is bonded to six O atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.42–2.45 Å. There are five inequivalent V sites. In the first V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.65–2.29 Å. In the second V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.63–2.38 Å. In the third V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.65–2.36 Å. In the fourth V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.65–2.30 Å. In the fifth V site, V is bonded to six O atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.12 Å. There are fourteen inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the third H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the fourth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the fifth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the sixth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the seventh H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the eighth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the ninth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the tenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the eleventh H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the twelfth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the thirteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fourteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are twenty-one inequivalent O sites. In the first O site, O is bonded in a trigonal non-coplanar geometry to three V atoms. In the second O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the third O site, O is bonded in a trigonal non-coplanar geometry to three V atoms. In the fourth O site, O is bonded in a water-like geometry to two V atoms. In the fifth O site, O is bonded in a single-bond geometry to one V atom. In the sixth O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the seventh O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the eighth O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the ninth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the tenth O site, O is bonded in a distorted bent 120 degrees geometry to two V atoms. In the eleventh O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the twelfth O site, O is bonded in a single-bond geometry to one V atom. In the thirteenth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the fourteenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the fifteenth O site, O is bonded in a water-like geometry to two V atoms. In the sixteenth O site, O is bonded to six V atoms to form edge-sharing OV6 octahedra. In the seventeenth O site, O is bonded in a distorted bent 120 degrees geometry to two V atoms. In the eighteenth O site, O is bonded in a distorted bent 120 degrees geometry to two V atoms. In the nineteenth O site, O is bonded in a distorted linear geometry to one Na and one V atom. In the twentieth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the twenty-first O site, O is bonded in a single-bond geometry to one V atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Mn-induced spin glass behavior in metallic Ir 3 Sn 7-x Mn x

Transition metal stannides are usually semiconductors with a narrow band gap. We report experimental investigation on metallic Ir 3 Sn 7– x Mn x ( x = 0 and 0.56). Single crystal x-ray diffraction refinement indicates that Ir 3 Sn 7– x Mn x crystals form a cubic structure (space group Im 3 - m ) with the lattice parameter a = 9.362(4) Å for x = 0 and 9.328(6) Å for x = 0.56. The electrical resistivity shows metallic behavior between 2 K and 300 K with T 2 dependence at T < 30 K for x = 0, reflecting the Fermi-liquid ground state. While Ir 3 Sn 7 exhibits weak diamagnetism, partial substitution of Sn by Mn results in spin glass behavior in Ir 3 Sn 7- x Mn x below T g ~ 13 K for x = 0.56. Remarkably, an upturn in the resistivity is observed in x = 0.56 below ~2 T g , suggesting strong spin fluctuation. This fluctuation is suppressed by the application of magnetic field, which is reflected in the observation of negative magnetoresistance. The unusual properties that emerge due to Mn doping are discussed.

Physics↗
DOE OSTI2025

Synthesis and Crystal Structures of Alkali (Na, Rb, Cs) Iron Phosphate Crystals

Three alkali-containing diphosphate crystals of A FeP 2 O 7 (A = Na, Rb, Cs) were synthesized through melt-crystallization. The crystal structures were determined using single-crystal X-ray diffraction (XRD) data. The synthesized diphosphates crystallized within the P 2 1 /c space group, and the structural parameters were compared to literature data of other A FeP 2 O 7 crystals within the P 2 1 /c space group.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Yield and Survival of 19 Cultivars of Willow (Salix spp.) Biomass Crops over Eight Rotations

This study reveals patterns of yield and survival of short-rotation coppice (SRC) willow cultivars over eight rotations (1993–2019). Cultivars fell into four broad categories: commercial, released, stable, and decline. SV1, the singular cultivar that advanced to commercial deployments, had first-rotation yields of 8.9 Mg ha−1 a−1, peaking at 15.2 Mg ha−1 a−1 by the fourth. Mean yields from rotations 2–8 were still 36% above first-rotation yields, confirming the commercial potential for this cultivar over 26 years. The released group (four cultivars) had stable yields over six rotations (approximately 3 to 7 Mg ha−1 a−1), rising to match commercial yields (10 Mg ha−1 a−1) between the sixth and eighth rotation. Most of the cultivars were in the stable group that had relatively consistent yields over time. First-rotation yields in this group were approximately 5 Mg ha−1 a−1, and average yield increased by 23% for rotations 2–8. The two cultivars in the decline group were impacted by disease and browsing that lowered survival and growth. These findings are crucial for understanding willow systems’ potential over their full lifespan as a bioenergy crop, which is a crucial input into yield, economic, and environmental models.

Santucci, Shane↗
DOE OSTI2020

Crystal and magnetic structures of magnetic topological insulators MnBi 2 Te 4 and MnBi 4 Te 7

Using single-crystal neutron diffraction, we present a systematic investigation of the crystal structure and magnetism of the van der Waals topological insulators MnBi 2 Te 4 and MnBi 4 Te 7 , where rich topological quantum states have been recently predicted and observed. Structural refinements reveal that considerable Bi atoms occupied on the Mn sites in both materials, distinct from the previously reported antisite disorder. We show unambiguously that MnBi 2 Te 4 orders antiferromagnetically below 24 K, featured by a magnetic symmetry R I - 3 c , while MnBi 4 Te 7 is antiferromagnetic below 13 K with a magnetic space group P c - 3 c 1 . They both present antiferromagnetically coupled ferromagnetic layers with spins along the c axis. We put forward a stacking rule for the crystal structure of an infinitely adaptive series MnBi 2 n Te 3 n + 1 ( n ≥ 1 ) with a building unit of [ Bi 2 Te 3 ] . Overall, by comparing the magnetic properties between MnBi 2 Te 4 and MnBi 4 Te 7 , together with recent density-functional theory calculations, we concluded that a two-dimensional magnetism limit might be realized in the derivatives. Our work may promote theoretical studies of topological magnetic states in the series of MnBi 2 n Te 3 n + 1 .

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Materials Data on Li12(WO4)7 by Materials Project

Li12(WO4)7 crystallizes in the cubic P-43m space group. The structure is three-dimensional. Li is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Li–O bond distances ranging from 2.00–2.52 Å. There are two inequivalent W sites. In the first W site, W is bonded to six O atoms to form distorted edge-sharing WO6 octahedra. There are three shorter (1.83 Å) and three longer (2.17 Å) W–O bond lengths. In the second W site, W is bonded in a tetrahedral geometry to four equivalent O atoms. All W–O bond lengths are 1.82 Å. There are three inequivalent O sites. In the first O site, O is bonded in a see-saw-like geometry to three equivalent Li and one W atom. In the second O site, O is bonded in a trigonal planar geometry to two equivalent Li and one W atom. In the third O site, O is bonded to three equivalent Li and three equivalent W atoms to form distorted edge-sharing OLi3W3 octahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3SrCu2C7(SN)7 by Materials Project

Cs3SrCu2C7(NS)7 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to two equivalent N3- atoms. Both Cs–N bond lengths are 3.17 Å. In the second Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are four shorter (3.75 Å) and four longer (4.03 Å) Cs–S bond lengths. Sr2+ is bonded in a 9-coordinate geometry to nine N3- atoms. There are a spread of Sr–N bond distances ranging from 2.74–2.86 Å. Cu1+ is bonded to four S2- atoms to form corner-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.32–2.37 Å. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a distorted linear geometry to one N3- and one S2- atom. The C–N bond length is 1.19 Å. The C–S bond length is 1.64 Å. In the second C4+ site, C4+ is bonded in a linear geometry to one N3- and one S2- atom. The C–N bond length is 1.18 Å. The C–S bond length is 1.66 Å. In the third C4+ site, C4+ is bonded in a distorted linear geometry to one N3- and one S2- atom. The C–N bond length is 1.18 Å. The C–S bond length is 1.65 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C4+ atom. In the second N3- site, N3- is bonded in a distorted linear geometry to one Sr2+ and one C4+ atom. In the third N3- site, N3- is bonded in a 1-coordinate geometry to one Cs1+, one Sr2+, and one C4+ atom. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to two equivalent Cu1+ and one C4+ atom. In the second S2- site, S2- is bonded in a 2-coordinate geometry to one Cs1+, one Cu1+, and one C4+ atom. In the third S2- site, S2- is bonded in a distorted water-like geometry to two equivalent Cs1+, one Cu1+, and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Emergence of heavy-fermion behavior and distorted square nets in partially vacancy-ordered Y 4 Fe x Ge 8 (1.0 ≤ x ≤ 1.5)

Disorders in intermetallic systems belonging to the CeNiSi 2 -family are frequently overlooked. Even compounds presumed to be stoichiometric, such as YFeGe 2 , can be misidentified. Here, in this study, we report a series of Y 4 Fe x Ge 8 (1.0 ≤ x ≤ 1.5) compounds and show, using high-resolution synchrotron X-ray diffraction, that they feature asymmetrical structural distortions in the Fe and Ge sites that lead to a superstructure with partially ordered Fe vacancies and distorted Ge square-net in the triclinic crystal system, space group P[1 with combining macron] with a = 11.4441(3) Å, b = 32.7356(7) Å, c = 11.4456(3) Å, α = 79.6330(10)°, β = 88.3300(10)°, and γ = 79.6350 (10)°. The unit cell is 16 times the conventional orthorhombic cell with the space group Cmcm. We identified the lower and upper limits for Fe in Y 4 Fe x Ge 8 (1.0 ≤ x ≤ 1.5). Our physical property measurements yielded a Sommerfeld coefficient γ = 39.8 mJ mole −1 K −2 , a Kadowaki–Woods ratio of 1.2 × 10 −5 μΩ cm mole 2 K 2 mJ −2 , and a Wilson ratio of 1.83, suggesting heavy fermion behavior in the absence of f electrons, a rather rare case. Furthermore, we observed strong spin frustration and noted findings indicating possible superconductivity associated with the Fe content.

Zhao, Hengdi [Argonne National Laboratory (ANL), A↗
DOE OSTI2021

Prediction of Solution Behavior via Calorimetric Measurements Allows for Detailed Elucidation of Polyoxometalate Transformation

The solution behavior of a polyoxometalate cluster, LiNa-U 24 Pp 12 (Li 24 Na 24 [(UO 2 O 2 ) 24 (P 2 O 7 ) 12 ]) that consists of 24 uranyl ions, peroxide groups, and 12 pyrophosphate linkers, was successfully predicted based on new thermodynamic results using a calorimetric method recently described for uranyl peroxide nanoclusters (UPCs), molybdenum blues, and molybdenum browns. The breakdown of LiNa-U 24 Pp 12 and formation of U 24 (Li 24 [UO 2 O 2 OH] 24 ) was monitored in situ via Raman spectroscopy using a custom heating apparatus. A combination of analytical techniques confirmed the simultaneous existence of U 24 Pp 12 and U 24 midway through the conversion process and U 24 as the single end product. The application of a molecular weight filter resulted in a complete and successful separation of UPCs from solution and, in conjunction with DOSY results, confirmed the presence of large intermediate cluster building blocks.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Te7As2F12 by Materials Project

(Te)7(AsF6)2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of twenty-eight tellurium molecules and eight AsF6 clusters. In each AsF6 cluster, As1+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of As–F bond distances ranging from 1.77–1.79 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As1+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As1+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As1+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one As1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C10F3 by Materials Project

(C)7(CF)3 crystallizes in the monoclinic Cc space group. The structure is zero-dimensional and consists of seventy-two fluoromethane molecules and one hundred and sixty-eight methane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaH18C9I(NO)3 by Materials Project

(Na2C9H14(NO)3)2(C3NH6O)4(C3NH3O)2(H2)7(I)4 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one 45358-43-8 molecule; two hydriodic acid molecules; four hydrogen molecules; one n,n-dimethylformamide molecule; one C3NH6O cluster; and one Na2C9H14(NO)3 cluster. In the C3NH6O cluster, there are three inequivalent C+0.33- sites. In the first C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.46 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.22 Å. In the second C+0.33- site, C+0.33- is bonded in a tetrahedral geometry to one N3- and three H1+ atoms. The C–N bond length is 1.47 Å. There are a spread of C–H bond distances ranging from 1.11–1.31 Å. In the third C+0.33- site, C+0.33- is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.32 Å. N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one H1+ atom. The H–H bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a distorted bent 120 degrees geometry to one C+0.33- and one H1+ atom. In the fifth H1+ site, H1+ is bonded in a bent 120 degrees geometry to one C+0.33- and one H1+ atom. The H–H bond length is 0.92 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one H1+ atom. O2- is bonded in a single-bond geometry to one C+0.33- atom. In the Na2C9H14(NO)3 cluster, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.53 Å. In the second Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.84 Å. There are nine inequivalent C+0.33- sites. In the first C+0.33- site, C+0.33- is bonded in a tetrahedral geometry to one N3- and three H1+ atoms. The C–N bond length is 1.50 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the second C+0.33- site, C+0.33- is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.32 Å. In the third C+0.33- site, C+0.33- is bonded in a distorted single-bond geometry to one C+0.33- and one N3- atom. The C–C bond length is 1.56 Å. The C–N bond length is 1.32 Å. In the fourth C+0.33- site, C+0.33- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.46 Å. All C–H bond lengths are 1.10 Å. In the fifth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.39 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.23 Å. In the sixth C+0.33- site, C+0.33- is bonded in a distorted trigonal planar geometry to one C+0.33-, one N3-, and two H1+ atoms. The C–N bond length is 1.44 Å. There is one shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the seventh C+0.33- site, C+0.33- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.46 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the eighth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.44 Å. The C–H bond length is 1.11 Å. The C–O bond length is 1.23 Å. In the ninth C+0.33- site, C+0.33- is bonded in a trigonal planar geometry to one N3-, one H1+, and one O2- atom. The C–N bond length is 1.33 Å. The C–H bond length is 1.10 Å. The C–O bond length is 1.27 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. In the second N3- site, N3- is bonded in a 3-coordinate geometry to three C+0.33- atoms. In the third N3- site, N3- is bonded in a trigonal planar geometry to three C+0.33- atoms. There are thirteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.33- atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+ and one C+0.33- atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Na1+ and one C+0.33- atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Na1+ and one C+0.33- atom.

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