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At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on PmNp by Materials Project

NpPm is Magnesium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Np is bonded to six equivalent Np and six equivalent Pm atoms to form NpPm6Np6 cuboctahedra that share corners with eighteen equivalent NpPm6Np6 cuboctahedra, edges with six equivalent NpPm6Np6 cuboctahedra, edges with twelve equivalent PmPm6Np6 cuboctahedra, faces with eight equivalent NpPm6Np6 cuboctahedra, and faces with twelve equivalent PmPm6Np6 cuboctahedra. All Np–Np bond lengths are 3.37 Å. All Np–Pm bond lengths are 3.55 Å. Pm is bonded to six equivalent Np and six equivalent Pm atoms to form PmPm6Np6 cuboctahedra that share corners with eighteen equivalent PmPm6Np6 cuboctahedra, edges with six equivalent PmPm6Np6 cuboctahedra, edges with twelve equivalent NpPm6Np6 cuboctahedra, faces with eight equivalent PmPm6Np6 cuboctahedra, and faces with twelve equivalent NpPm6Np6 cuboctahedra. All Pm–Pm bond lengths are 3.37 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GdNp3 by Materials Project

Np3Gd is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded to eight equivalent Np and four equivalent Gd atoms to form NpGd4Np8 cuboctahedra that share corners with twelve equivalent NpGd4Np8 cuboctahedra, edges with eight equivalent GdNp12 cuboctahedra, edges with sixteen equivalent NpGd4Np8 cuboctahedra, faces with four equivalent GdNp12 cuboctahedra, and faces with fourteen equivalent NpGd4Np8 cuboctahedra. All Np–Np bond lengths are 3.26 Å. All Np–Gd bond lengths are 3.26 Å. Gd is bonded to twelve equivalent Np atoms to form GdNp12 cuboctahedra that share corners with twelve equivalent GdNp12 cuboctahedra, edges with twenty-four equivalent NpGd4Np8 cuboctahedra, faces with six equivalent GdNp12 cuboctahedra, and faces with twelve equivalent NpGd4Np8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np2Tc3Ge4 by Materials Project

Np2Tc3Ge4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Np is bonded in a 10-coordinate geometry to two equivalent Tc and eight Ge atoms. There are one shorter (2.89 Å) and one longer (2.98 Å) Np–Tc bond lengths. There are a spread of Np–Ge bond distances ranging from 2.94–3.10 Å. There are two inequivalent Tc sites. In the first Tc site, Tc is bonded in a 7-coordinate geometry to two equivalent Np and five Ge atoms. There are a spread of Tc–Ge bond distances ranging from 2.49–2.60 Å. In the second Tc site, Tc is bonded to six Ge atoms to form distorted corner-sharing TcGe6 octahedra. The corner-sharing octahedral tilt angles are 22°. All Tc–Ge bond lengths are 2.55 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 8-coordinate geometry to four equivalent Np and four Tc atoms. In the second Ge site, Ge is bonded in a 10-coordinate geometry to four equivalent Np, four Tc, and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.86 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNp3 by Materials Project

MgNp3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Mg is bonded to twelve equivalent Np atoms to form MgNp12 cuboctahedra that share corners with twelve equivalent MgNp12 cuboctahedra, edges with twenty-four equivalent NpMg4Np8 cuboctahedra, faces with six equivalent MgNp12 cuboctahedra, and faces with twelve equivalent NpMg4Np8 cuboctahedra. All Mg–Np bond lengths are 3.24 Å. Np is bonded to four equivalent Mg and eight equivalent Np atoms to form NpMg4Np8 cuboctahedra that share corners with twelve equivalent NpMg4Np8 cuboctahedra, edges with eight equivalent MgNp12 cuboctahedra, edges with sixteen equivalent NpMg4Np8 cuboctahedra, faces with four equivalent MgNp12 cuboctahedra, and faces with fourteen equivalent NpMg4Np8 cuboctahedra. All Np–Np bond lengths are 3.24 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4Np3H8Cl7O10 by Materials Project

K4Np3H8O10Cl7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 1-coordinate geometry to two O2- and five Cl1- atoms. There are one shorter (2.74 Å) and one longer (3.01 Å) K–O bond lengths. There are a spread of K–Cl bond distances ranging from 3.12–3.36 Å. In the second K1+ site, K1+ is bonded in a 1-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of K–O bond distances ranging from 2.80–3.29 Å. There are a spread of K–Cl bond distances ranging from 3.13–3.42 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to four O2- and three Cl1- atoms. There are a spread of K–O bond distances ranging from 2.77–3.08 Å. There are a spread of K–Cl bond distances ranging from 3.14–3.29 Å. In the fourth K1+ site, K1+ is bonded in a 8-coordinate geometry to three O2- and five Cl1- atoms. There are a spread of K–O bond distances ranging from 2.90–3.35 Å. There are a spread of K–Cl bond distances ranging from 3.21–3.66 Å. There are three inequivalent Np5+ sites. In the first Np5+ site, Np5+ is bonded in a 7-coordinate geometry to four O2- and three Cl1- atoms. There are a spread of Np–O bond distances ranging from 1.83–2.62 Å. There are a spread of Np–Cl bond distances ranging from 2.81–2.89 Å. In the second Np5+ site, Np5+ is bonded in a 7-coordinate geometry to four O2- and three Cl1- atoms. There are a spread of Np–O bond distances ranging from 1.87–2.53 Å. There are a spread of Np–Cl bond distances ranging from 2.82–2.89 Å. In the third Np5+ site, Np5+ is bonded in a 2-coordinate geometry to four O2- and three Cl1- atoms. There are a spread of Np–O bond distances ranging from 1.83–2.58 Å. There are a spread of Np–Cl bond distances ranging from 2.80–2.90 Å. There are eight 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 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 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 1.00 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. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one Np5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Np5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Np5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Np5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+ and two Np5+ atoms. In the sixth O2- site, O2- is bonded in a water-like geometry to one K1+, one Np5+, and two H1+ atoms. In the seventh O2- site, O2- is bonded in a water-like geometry to one K1+, one Np5+, and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to two Np5+ atoms. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to one K1+, one Np5+, and two H1+ atoms. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Np5+ and two H1+ atoms. There are seven inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to two K1+ and two equivalent Np5+ atoms to form distorted edge-sharing ClK2Np2 trigonal pyramids. In the second Cl1- site, Cl1- is bonded in a 4-coordinate geometry to two K1+ and two equivalent Np5+ atoms. In the third Cl1- site, Cl1- is bonded in a 5-coordinate geometry to four K1+ and one Np5+ atom. In the fourth Cl1- site, Cl1- is bonded in a 5-coordinate geometry to four K1+ and one Np5+ atom. In the fifth Cl1- site, Cl1- is bonded in a 3-coordinate geometry to two equivalent K1+ and one Np5+ atom. In the sixth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to one K1+ and one Np5+ atom. In the seventh Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two K1+ and one Np5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpCd11 by Materials Project

NpCd11 crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded in a 12-coordinate geometry to twenty Cd atoms. There are a spread of Np–Cd bond distances ranging from 3.55–3.86 Å. There are five inequivalent Cd sites. In the first Cd site, Cd is bonded in a cuboctahedral geometry to twelve Cd atoms. All Cd–Cd bond lengths are 3.13 Å. In the second Cd site, Cd is bonded in a 6-coordinate geometry to three equivalent Np and six Cd atoms. There are three shorter (2.93 Å) and three longer (2.94 Å) Cd–Cd bond lengths. In the third Cd site, Cd is bonded in a distorted q6 geometry to two equivalent Np and eight Cd atoms. There are two shorter (2.93 Å) and four longer (3.00 Å) Cd–Cd bond lengths. In the fourth Cd site, Cd is bonded in a 10-coordinate geometry to one Np and nine Cd atoms. All Cd–Cd bond lengths are 3.13 Å. In the fifth Cd site, Cd is bonded in a 10-coordinate geometry to one Np and nine Cd atoms. There are four shorter (3.00 Å) and four longer (3.13 Å) Cd–Cd bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Neptunium redox speciation and determination of its total concentration in dissolved fuel simulant solutions by spectrophotometry

Here, two new approaches to measure Np concentration in dissolved used nuclear fuel simulant (aqueous feed for PUREX process) by spectrophotometry are developed. The first approach is based on chemical reduction of Np in the feed to its tetravalent state using ascorbic acid with simultaneous conversion of Pu(IV) to Pu(III). Interfering effects from light absorbing fission and corrosion products are accounted for by measuring optical absorbance spectrum of aqueous raffinate after extraction of U, Np, and Pu by tributyl phosphate in dodecane. The second approach uses no chemical treatment at all and relies on spontaneous valency adjustment of Np to Np(V) by dilution of the feed with water to reduce its acidity to low decimolar range of nitric acid concentration. Results of Np determination in the feed by spectrophotometry are in good agreement with its concentration measured by ICP-MS.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2022

Design Considerations for Controlling Silicon Nanoparticle Nucleation and Growth in a Nonthermal Plasma

Controlling the nucleation and growth of nanoparticles in low temperature plasma systems is imperative for controlling nanoparticle size distributions; and for some applications such as deposition and etching in microelectronic processing, preventing particle contamination. In this work, silicon nanoparticle (NP) production from silane is used as a model system to investigate the nucleation process. Although the mechanisms responsible for silicon NP nucleation and growth have been studied, it is unclear how controllable system parameters (e.g., pressure, system geometry, and gas composition) can be used to inhibit or promote NP formation. For example, the transport of reactive silane species is expected to significantly affect the feed fraction of silane required to nucleate silicon NP (the nucleation onset fraction) due to losses at the reactor walls. In this work, NP mass density was determined as a function of system pressure, gas composition, and reactor diameter for a tubular flow-through radiofrequency (RF) plasma using Ar/H2/He/SiH4 gas mixtures. A quartz crystal microbalance (QCM) impactor was developed to measure the total aerosol mass density downstream of the plasma and thereby identify the nucleation onset and its dependence on process parameters. Finally, a reaction mechanism was developed and incorporated into a global plasma chemistry model to better understand the nucleation onset and NP growth.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Theoretical underpinnings of CP-violation at the high-energy frontier

We present a general analysis for the discovery potential of CP-violation (CPV) searches in scattering processes at TeV-scale colliders in an effective field theory framework, using the SMEFT basis for higher dimensional operators. In particular, we systematically examine the CP-violating sector of the SMEFT framework in some well motivated limiting cases, based on flavour symmetries of the underlying heavy theory. We show that, under naturality arguments of the underlying new physics (NP) and in the absence of (or suppressed) flavour-changing interactions, there is only a single operator, Q tΦ = Φ † Φ($\overline{q}$ 3 t) $\tilde{\phi}$ which alters the top-Yukawa coupling, that can generate a non-vanishing CP-violating effect from tree-level SM×NP interference terms. We find, however, that CPV from Q tΦ = Φ † Φ($\overline{q}$ 3 t) $\tilde{\phi}$ is expected to be at best of Ο (1%) and, therefore, very challenging if at all measurable at the LHC or other future high-energy colliders. We then conclude that a potentially measurable CP-violating effect of Ο (10%) can arise in high-energy scattering processes only if flavour-changing interactions are present in the underlying NP; in this case a sizable CPV can be generated at the tree-level by pure NP×NP effects and not from SM×NP interference. We provide several examples of CPV at the LHC and at a future e + s - collider to support these statements.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

The effect of TiO2 nanoparticles on antral follicles is dependent on the nanoparticle internalization rate

Abstract Titanium dioxide nanoparticles (TiO2 NPs) are among the most widely produced metallic NPs due to commercial and industrial applications in products including food, cosmetics, paints, and plastics. TiO2 NPs are released into the environment posing health risks for humans and wildlife. Widespread uses have raised concerns about the potential toxicity of TiO2 NPs in reproduction. The ovary is an important endocrine organ responsible for sex steroid hormone production and folliculogenesis. NPs can reach the ovary, but limited information is available regarding NP toxicity and its effects on ovarian antral follicles. Thus, we tested the hypothesis that exposure to TiO2 NP affects sex hormone synthesis, oxidative stress, and antioxidant response in ovarian antral follicles in vitro. In addition, we characterized the NP internalization in the antral follicles over time to determine any association between NP internalization and effects on the antral follicle. Antral follicles were exposed to vehicle control or TiO2 NPs (5, 25, and 50 µg/ml) for 96 h. The lowest NP concentration (5 µg/ml) showed no internalization and no effects in antral follicles. The 25-µg/ml concentration had the highest internalization rate, leading to increased mRNA ratio of Bax to Bcl2. Interestingly, the highest concentration (50 µg/ml) showed lower internalization compared with the 25 µg/ml, with altered levels of steroidogenic involved genes and increased levels of progesterone and testosterone compared with control. In conclusion, these data suggest that TiO2 NP is internalized in antral follicles as the first step process in impairing follicle functions.

Santacruz-Márquez, Ramsés (ORCID:0000000225239064)↗
DOE OSTI2020

Ring patterns generated by an expanding colloidal meniscus

The drop-and-dry is a common technique allowing for creation of periodic nanoparticle (NP) structures for sensing, photonics, catalysis, etc. However, the reproducibility and scalability of this approach for fabrication of NP-based structures faces serious challenges due to the complexity of the simple, at first glance, evaporation process. In this work we study the effect of the spatial confinement on the NP self-assembly under slow solvent evaporation, when the air-liquid-substrate contact line (CL) expands from the center towards the walls of a cylindrical cell, forming a toroid. Using in situ video monitoring of the stick-slip CL motion, we find regular hydrodynamic perturbations in the meniscus, and reveal fine details of the formation of quasiperiodic rings of close packed NP layers. We report that drying of the toroidal NP droplet has a number of important differences from drying of the classical hemispherical colloidal drops. In toroidal drops we observe linear-in-time average meniscus motion, in contrast to the hemispherical drops where the meniscus moves as a square root of time. While both droplet geometries produce NP ring patterns, the ring width for the toroidal drop decreases with increasing ring radius, while it decreases with decreasing the radius of the hemispherical drop. We suggest that free ligands are the main cause of the Marangoni instabilities driving the periodic vorticity in the meniscus. Finally, we show that the usually ignored contact line tension may yield a considerable contribution to the CL pinning causing the CL slip-stick motion and the ring formation.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Assessing subtle variations in the actinyl oxo reactivity through characterization of neptunyl complexes. Final Report

Formation of the actinyl cation, [An(V,VI)O 2 ] n+ (n = 1,2), imparts unique chemical properties to the lighter actinide elements (U, Np, and Pu) that has yet to be fully understood. The axial O atoms (oxo) of the [An(VI)O 2 ] 2+ are considered weak Lewis bases that exhibit only meager interact with other metal cations and regarded as poor hydrogen acceptors for nearby water molecules. Oxo atoms of [An(V)O 2 ] + should engage in stronger bonding interactions due to a higher degree of Lewis basicity, but the actual interactions have yet to be fully explored. Intermolecular interactions can impact radionuclide separations, corrosion of spent fuel, and mobility of actinides in environmental systems; there is, therefore, a critical need to understand how the subtle difference in electronic properties of the An(V) and An(VI) metal center influence actinyl chemistry. The objective of this proposal was to determine the chemical components that influence the intermolecular interactions occurring between neptunyl ([Np(V)O 2 ] + and [Np(VI)O 2 ] 2+ ) cations and neighboring species. My overall hypothesis was that the intermolecular attraction that occurs between the neptunyl oxo atoms and neighboring species (H atoms, low-valent cations, actinyl cations) is primarily controlled by the electronic properties of the actinyl cation, but can be further influenced by the electron donating properties of the equatorial ligands. The hypothesis was tested through the following research objectives: (1) Determine the fundamental differences in H-bonding between Np(V)O 2+ and Np(VI)O 2 2+ and neighboring donor molecules; (2) Identify the major differences in bonding between low-valence metal cations and neptunyl oxo groups, and (3) Assess the impact of the equatorial ligand on the formation of cation-cation interactions within molecular species. Major outcomes of the research include: (1) More precisely identifying oxo interactions (actinyl-cation; actinyl-actinyl, actinyl-hydrogen) and the factors that impact the vibrational modes for actinyl cation; (2) Identification of H-bonding modes for the [An(V,VI)O 2 ] n+ (n = 1,2), with direct H-bonding interactions to the oxo group of the Np(V)O 2+ cation more prevalent than in hexavalent species and recognition of the importance of H-bonding networks, that can impart bond asymmetry and activation of vibrational modes with the actinyl moiety; (3) Delineation of the importance of charge density for engaging the cation-oxo interaction for both pentavalent and hexavalent species; (4) Determining the importance of sterics and ligand binding in formation of specific actinyl-actinyl interactions and the resulting vibrational modes associated with this bonding motify and (5) Understanding how the functionalization of the ligand can impact redox stability of neptunyl cations. Deliverables from this work include 11 peer-reviewed manuscripts and 13 (including six by graduate students) oral/poster presentations.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Modulation of springtime surface sensible heating over the Tibetan Plateau on the interannual variability of East Asian dust cycle

Previous observational evidence and numerical simulations have revealed that the surface sensible heating in spring (March–April–May, MAM) over the Tibetan Plateau (TPSH) can affect the Asian regional hydrological cycle, surface energy balance, and climate through altering atmospheric heat source of the Tibetan Plateau (TP). This study aims to investigate the impacts of MAM TPSH on the interannual variability of East Asian dust cycle by using CAM4-BAM (version 4 of the Community Atmosphere Model coupled to a bulk aerosol model), MERRA-2 (version 2 of the Modern-Era Retrospective analysis for Research and Applications) surface dust concentration, and TPSH measurements. Our simulations show that the surface dust concentrations over the East Asian (EA) dust source region and over the northwestern Pacific (NP) in MAM are significantly positively correlated with TPSH, with regionally averaged correlation coefficients of 0.49 for EA and 0.44 for NP. Similar positive correlations are also shown between the MAM TPSH measurements averaged over the 73 observation sites and the surface dust concentration from MERRA-2. Simulation-based comparisons between strongest and weakest TPSH years reveal that, the MAM surface dust concentration in the strongest TPSH years increases with relative differences of 13.1 % over EA and 36.9 % over NP. These corresponding differences are found in MERRA-2 with 22.9 % and 13.3 % over EA and NP, respectively. Further simulated results show that the processes of whole dust cycles (e.g., dust loading, emission, and transport, as well as dust deposition) are also significantly enhanced during the strongest TPSH years over EA and NP. Through enhancing the TP heat source, stronger TPSH in MAM generates an anticyclonic anomaly in middle and upper troposphere over the TP and over the downstream Pacific region, respectively. These atmospheric circulation anomalies induced by the increased TPSH result in increasing the westerly winds over both EA and NP, which in turn increases dust emissions over the dust source, and dust transport over these two regions, as well as the regional dust cycles. These results suggest that addressing the East Asian dust changes in the future climates requires considering not only increasing greenhouse gas emissions but also the variations of the TP's heat source under global warming.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on NpAl4 by Materials Project

NpAl4 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Np is bonded in a 11-coordinate geometry to thirteen Al atoms. There are a spread of Np–Al bond distances ranging from 3.03–3.13 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to three equivalent Np and seven Al atoms. There are a spread of Al–Al bond distances ranging from 2.62–2.95 Å. In the second Al site, Al is bonded to four equivalent Np and eight Al atoms to form a mixture of distorted face, edge, and corner-sharing AlNp4Al8 cuboctahedra. There are two shorter (3.07 Å) and four longer (3.12 Å) Al–Al bond lengths. In the third Al site, Al is bonded in a 3-coordinate geometry to three equivalent Np and ten Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np2InNi2 by Materials Project

Np2Ni2In crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Np is bonded in a 6-coordinate geometry to six equivalent Ni and four equivalent In atoms. There are two shorter (2.77 Å) and four longer (2.86 Å) Np–Ni bond lengths. All Np–In bond lengths are 3.27 Å. Ni is bonded in a 9-coordinate geometry to six equivalent Np, one Ni, and two equivalent In atoms. The Ni–Ni bond length is 2.63 Å. Both Ni–In bond lengths are 2.90 Å. In is bonded to eight equivalent Np and four equivalent Ni atoms to form a mixture of corner and face-sharing InNp8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np2Si4Tc3 by Materials Project

Np2Tc3Si4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Np+3.50+ is bonded in a 2-coordinate geometry to two equivalent Tc+2.33- and two equivalent Si atoms. There are one shorter (2.93 Å) and one longer (2.96 Å) Np–Tc bond lengths. There are one shorter (2.92 Å) and one longer (2.94 Å) Np–Si bond lengths. There are two inequivalent Tc+2.33- sites. In the first Tc+2.33- site, Tc+2.33- is bonded in a 7-coordinate geometry to two equivalent Np+3.50+ and five Si atoms. There are a spread of Tc–Si bond distances ranging from 2.44–2.50 Å. In the second Tc+2.33- site, Tc+2.33- is bonded in a 12-coordinate geometry to six Si atoms. There are four shorter (2.51 Å) and two longer (2.56 Å) Tc–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 6-coordinate geometry to two equivalent Np+3.50+ and four Tc+2.33- atoms. In the second Si site, Si is bonded in a 4-coordinate geometry to four Tc+2.33- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs7Np3(Cl2O)6 by Materials Project

Cs7Np3(OCl2)6 crystallizes in the cubic I-43d space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 3-coordinate geometry to three equivalent O2- and six equivalent Cl1- atoms. All Cs–O bond lengths are 3.24 Å. There are three shorter (3.79 Å) and three longer (3.88 Å) Cs–Cl bond lengths. In the second Cs1+ site, Cs1+ is bonded to eight equivalent Cl1- atoms to form distorted corner-sharing CsCl8 hexagonal bipyramids. There are four shorter (3.61 Å) and four longer (3.64 Å) Cs–Cl bond lengths. Np+5.67+ is bonded in a distorted linear geometry to two equivalent O2- and four equivalent Cl1- atoms. Both Np–O bond lengths are 1.81 Å. All Np–Cl bond lengths are 2.70 Å. O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and one Np+5.67+ atom. Cl1- is bonded in a 1-coordinate geometry to four Cs1+ and one Np+5.67+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpNiSn by Materials Project

NpNiSn crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Np is bonded in a 1-coordinate geometry to six equivalent Ni and six equivalent Sn atoms. There are a spread of Np–Ni bond distances ranging from 2.82–3.38 Å. There are a spread of Np–Sn bond distances ranging from 3.15–3.21 Å. Ni is bonded in a 10-coordinate geometry to six equivalent Np and four equivalent Sn atoms. There are a spread of Ni–Sn bond distances ranging from 2.58–2.71 Å. Sn is bonded in a 10-coordinate geometry to six equivalent Np and four equivalent Ni atoms.

36 MATERIALS SCIENCE↗