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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Das ist der HAMMER: consistent new physics interpretations of semileptonic decays

Abstract Precise measurements of $$b\rightarrow c\tau \bar{\nu }$$ b → c τ ν ¯ decays require large resource-intensive Monte Carlo (MC) samples, which incorporate detailed simulations of detector responses and physics backgrounds. Extracted parameters may be highly sensitive to the underlying theoretical models used in the MC generation. Because new physics (NP) can alter decay distributions and acceptances, the standard practice of fitting NP Wilson coefficients to SM-based measurements of the $$R(D^{(*)})$$ R ( D ( ∗ ) ) ratios can be biased. The newly developed software tool enables efficient reweighting of MC samples to arbitrary NP scenarios or to any hadronic matrix elements. We demonstrate how allows avoidance of biases through self-consistent fits directly to the NP Wilson coefficients. We also present example analyses that demonstrate the sizeable biases that can otherwise occur from naive NP interpretations of SM-based measurements. The library is presently interfaced with several existing experimental analysis frameworks and we provide an overview of its structure.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Implementing belowground controls on nutrient uptake in ELMv2-SPRUCE improves representation of a boreal peatland ecosystem

Boreal peatlands store 13 %–32 % of the global soil carbon (C) stock, a service dependent on plant-mycorrhizal fungi associations. In these nutrient poor systems, ectomycorrhizal and ericoid mycorrhizal fungi supply up to >80 % of the nutrient requirements of their plant hosts, partly with mined nitrogen (N) and phosphorus (P) from soil organic matter that are otherwise inaccessible to plants. Despite the ecological significance, mycorrhizal associations are only represented in a few land surface or ecosystem models. We modify the peatland branch of version 2 of the Energy Exascale Earth System Land Model (ELMv2-SPRUCE) to replace the default photosynthesis-driven inorganic N and P (NP) uptake process with a more realistic representation of the process via three pathways: (1) direct inorganic NP uptake by uncolonized fine roots, (2) indirect inorganic NP acquisition and (3) indirect NP acquisition from organic sources by mycorrhizal roots. We systematically evaluated the performance of the default and modified models with field observations from a whole ecosystem warming and carbon dioxide fertilization experimental site: Spruce and Peatland Responses Under Changing Environment (SPRUCE), in northern Minnesota, USA. The modified model reduces the underestimation of the growth response of shrubs in the default model to warming from 40 %–80 % to 17 %–35 % and reduces the overall relative absolute error on C fluxes from 1.61 to 1.54 in calibration. Improvements on modeled shrub growths and shrub-moss community net ecosystem exchanges are also seen in validation. The improved growth response of shrubs to warming is accompanied by several-fold increase in direct inorganic NP uptake and decrease in fungal colonization rate. The modified model simulates a smaller magnitude of transition of the ecosystem from C sink to C source under warming due to alleviation of plant nutrient limitation. Equifinality analysis shows the newly added parameters in the modified model can be constrained by the observed C fluxes. Sensitivity analysis shows the newly added parameters have stronger statistical interactions than the preexisting parameters in the default model. Overall, the modified model is an improvement over the default ELMv2-SPRUCE and will be a useful tool for understanding boreal peatland change.

Wang, Yaoping [Oak Ridge National Laboratory (ORNL↗
NASA NTRS1981

SRB dewatering set

The system components and operation of the space shuttle solid rocket booster (SRB) dewatering set are described. The SRB dewatering set consists of a nozzle plug, control console, remote control unit, power distribution unit, umbilical cable, interconnect cables, and various handling and storage items. The nozzle plug (NP) is a remotely controlled, tethered underwater vehicle that is launched from the retrieval vessel (RV) by a crane, descends down the side of the SRB, and is positioned below the SRB nozzle. A TV camera mounted at the top of the NP central core is used by the control console operator to visually guide the NP during descent and docking. The NP is then driven up and locked into the nozzle. Compressed air is passed through the umbilical from the RV, through the NP and into the SRB motor. The water inside the SRB is expelled causing the SRB to rotate to a near horizontal attitude on the surface of the water.

Wickham, R. E.↗
NASA NTRS1993

Effect of aerobic capacity on Lower Body Negative Pressure (LBNP) tolerance in females

This investigation determined whether a relationship exists in females between: (1) aerobic capacity and Lower Body Negative Pressure (LBNP); and (2) aerobic capacity and change in LBNP tolerance induced by bed rest. Nine females, age 27-47 (34.6 plus or minus 6.0 (Mean plus or minus SD)), completed a treadmill-graded exercise test to establish aerobic capacity. A presyncopal-limited LBNP test was performed prior to and after 13 days of bed rest at a 6 deg head-down tilt. LBNP tolerance was quantified as: (1) the absolute level of negative pressure (NP) tolerated for greater than or equal to 60 sec; and (2) Luft's Cumulative Stress Index (CSI). Aerobic capacity was 33.3 plus or minus 5.0 mL/kg/min and ranged from 25.7 to 38.7. Bed rest was associated with a decrease in NP tolerance (-9.04 1.6 kPa(-67.8 plus or minus 12.0 mmHg) versus -7.7 1.1 kPa(-57.8 plus or minus 8.33 mmHg); p = 0.028) and in CSI (99.4 27.4 kPa min(745.7 plus or minus 205.4 mmHg min) versus 77.0 16.9 kPa min (577.3 plus or minus mmHg min); p = 0.008). The correlation between aerobic capacity and absolute NP or CSI pre-bed rest did not differ significantly from zero (r = -0.56, p = 0.11 for NP; and r = -0.52, p = 0.16 for CSI). Also, no significant correlation was observed between aerobic and pre- to post-rest change for absolute NP tolerance (r = -0.35, p = 0.35) or CSI (r = -0.32, p = 0.40). Therefore, a significant relationship does not exist between aerobic capacity and orthostatic function or change in orthostatic function induced by bed rest.

Moore, Alan D., Jr.↗
NASA NTRS1993

Pigmenting agents in Martian soils: inferences from spectral, Mossbauer, and magnetic properties of nanophase and other iron oxides in Hawaiian palagonitic soil PN-9

We have examined a Hawaiian palagonitic tephra sample (PN-9) that has spectroscopic similarities to Martian bright regions using a number of analytical techniques, including Mossbauer and reflectance spectroscopy, X-ray diffraction, instrumental neutron activation analysis, electron probe microanalysis, transmission electron microscopy, and dithionite-citrate-bicarbonate extraction. Chemically, PN-9 has a Hawaiitic composition with alkali (and presumably silica) loss resulting from leaching by meteoric water during palagonitization; no Ce anomaly is present in the REE pattern. Mineralogically, our results show that nanophase ferric oxide (np-Ox) particles (either nanophase hematite (np-Hm) or a mixture of ferrihydrite and np-Hm) are responsible for the distinctive ferric doublet and visible-wavelength ferric absorption edge observed in Mossbauer and reflectivity spectra, respectively, for this and other spectrally similar palagonitic samples. The np-Ox particles appear to be imbedded in a hydrated aluminosilicate matrix material; no evidence was found for phyllosilicates. Other iron-bearing phases observed are titanomagnetite, which accounts for the magnetic nature of the sample; olivine; pyroxene; and glass. By analogy, np-Ox is likely the primary pigmenting agent of the bright soils and dust of Mars.

Minerals/analysis↗
NASA NTRS2024

Pressure Deficit in Gale Crater and a Larger Northern Polar Cap After the MY34 Global Dust Storm

We describe the model-independent analysis technique of Mars Science Laboratory (MSL) pressure and Mars Climate Sounder (MCS) data in de la Torre Juárez et al. (2019, https://doi.org/10.22541/essoar.169945479.90436599/v1) that compared multiple years of surface pressures on Gale before, during, and after the Global Dust Storm of Mars Year 34. The analysis found (a) representative pressure scale heights over Gale; (b) that the storm was followed by a pressure deficit at Gale; (c) the following C storms did not eliminate the deficit; (d) changes in the duration of the polar caps condensation seasons, with an early start of the North Polar (NP) ice cap growing season the year before the Great Dust Storm (GDS) and a late signature of the end of the expansion season thereafter, changes consistent with a larger growth phase of the NP cap; (e) MCS observed a larger than usual NP cap; and (f) cold temperature anomalies over the NP and warm over the Southern Pole after the storm. We also show that the analysis of observed MSL pressure data alone filters out effects on the pressure signal that are attributable to dynamical and orographic processes in a recent model analysis that makes similar interpretations as our 2019 study. One additional Mars year of observations is included to eliminate early concerns about sensor drifts. Noting that a similar NP anomaly was observed with MCS data after the last early GDS in MY25, and not the later GDS of MY27, the results suggest a possible unique effect of early GDSs.

Manuel de la Torre Juárez↗
DOE OSTI2020

Contaminant Migration Modeling to Support the In Situ Decommissioning of Hardened Nuclear Facilities - 20215

The decommissioning of hardened nuclear facilities provides a unique challenge in balancing current worker dose with exposure to future receptors and media. In situ decommissioning (ISD) is a cost-effective and safe option for the closure of such facilities but requires a detailed understanding of the threat that radioactive and hazardous constituents remaining in the facilities pose to groundwater and surrounding surface water. The Savannah River Site (SRS) extensively employs contaminant migration models within the decommissioning process to develop site-specific removal, grouting, and monitoring strategies in support of safe and effective final end states of nuclear facilities. This work discusses the use of contaminant migration modeling in the ISD process at SRS, including specific examples from the closure of P-Reactor and R-Reactor, Building 235-F, F-Canyon and F/H Laboratory Complex. Migration models developed during the closure of P-Reactor and R-Reactor were divided into four source areas: the reactor vessel, the process area, the disassembly basin, and the purification wing. Each source area was assigned a specific inventory and migration pathway and was then subject to varying hypothetical removal, capping, and grouting schemes. Modeling indicated that groundwater Maximum Concentration Limits (MCLs) might be exceeded if no action was taken for eleven and ten constituents of concern (COCs) at P-Reactor and R-Reactor, respectively. These exceedances could occur in as few as 200 to 500 years. Alternatively, the migration modeling demonstrated that the selected ISD actions reduced contaminant mobility which allowed for significant radioactive decay and resulted in fewer predicted exceedances of groundwater MCLs (five COCs for P-Reactor; eight COCs for R-Reactor). In response to the modeling results for P-Reactor and R-Reactor, effectiveness monitoring programs were developed to target contaminants, specific to each reactor, that may migrate to groundwater. Contaminant migration modeling also revealed that roof collapse was a large factor in the release of COCs to the environment, giving rise to roof improvements, and an inspection and vegetation control program to ensure roof stability over time. Contaminant migration modeling is also aiding in the closure planning for hardened facilities in F Area. Building 235-F housed the Actinide Billet Line, which produced Np-237 billets for irradiation in SRS reactors, and the Plutonium Fuel Form (PuFF) facility that produced Pu-238 heat sources for the space program. As a result of these missions, areas within Building 235-F contain considerable residual amounts of both Pu-238 and Np-237. Contaminant migration modeling of Building 235-F was originally performed in 2012 to identify the feasibility of ISD and the amount of radioactive material removal required to prevent the exceedance of groundwater MCLs. The original model indicated that a 60% reduction in the PuFF facility Pu-238 inventory could keep groundwater concentrations below standards, while Np-237 did not pose a threat to groundwater. However, updates to the model with an emphasis on source impact pathways revealed that, due to the orientation of the source areas relative to groundwater flow, no amount of reasonable removal of Pu-238 would keep groundwater concentrations below MCLs and that Np-237 could be a large contributor to localized MCL exceedances. With this insight, the refined 2019 model is being used to assist in the development of grouting plans specific to each facility source area, where bentonite may be utilized to slow the migration of Pu-238 and its daughter products from the PuFF facility and a reducing grout may decrease Np-237 transport by ensuring the nuclide remains in the less mobile +IV oxidation state. The beginning phases of contaminant migration modeling are underway for F-Canyon and associated facilities using lessons learned from the Reactors and Building 235-F. A contaminant migration pathway, similar to the pathway used for the reactor vessels, is being developed for the hot and warm canyons. The F-Canyon inventories are being spatially refined to identify specific and localized source zones, comparable to Building 235-F, that may impact groundwater. Contaminant migration modeling provides vital input within the ISD process, from facility investigation to post closure effectiveness monitoring, making it a valuable tool in the development of safe and effective end states for hardened nuclear facilities at SRS. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Compact Peptoid Molecular Brushes for Nanoparticle Stabilization

Controlling the interfaces and interactions of colloidal nanoparticles (NPs) via tethered molecular moieties is crucial for NP applications in engineered nanomaterials, optics, catalysis, and nanomedicine. Despite a broad range of molecular types explored, there is a need for a flexible approach to rationally vary the chemistry and structure of these interfacial molecules for controlling NP stability in diverse environments, while maintaining a small size of the NP molecular shell. Here, we demonstrate that low-molecular-weight, bifunctional comb-shaped, and sequence-defined peptoids can effectively stabilize gold NPs (AuNPs). The generality of this robust functionalization strategy was also demonstrated by coating of silver, platinum, and iron oxide NPs with designed peptoids. Each peptoid (PE) is designed with varied arrangements of a multivalent AuNP-binding domain and a solvation domain consisting of oligo-ethylene glycol (EG) branches. Among designs, a peptoid (PE5) with a diblock structure is demonstrated to provide a superior nanocolloidal stability in diverse aqueous solutions while forming a compact shell (similar to 1.5 nm) on the AuNP surface. We demonstrate by experiments and molecular dynamics simulations that PE5-coated AuNPs (PE5/AuNPs) are stable in select organic solvents owing to the strong PE5 (amine)-Au binding and solubility of the oligo-EG motifs. At the vapor-aqueous interface, we show that PE5/AuNPs remain stable and can self-assemble into ordered 2D lattices. The NP films exhibit strong near-field plasmonic coupling when transferred to solid substrates.

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

Materials Data on NpAl2Pd5 by Materials Project

NpPd5Al2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Pd atoms to form a mixture of corner and face-sharing NpPd12 cuboctahedra. There are four shorter (2.95 Å) and eight longer (3.02 Å) Np–Pd bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a distorted square co-planar geometry to four equivalent Np atoms. In the second Pd site, Pd is bonded in a 6-coordinate geometry to two equivalent Np and four equivalent Al atoms. There are two shorter (2.58 Å) and two longer (2.64 Å) Pd–Al bond lengths. Al is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs2Np2PO4F7 by Materials Project

Cs2Np2PO4F7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 1-coordinate geometry to two O2- and six F1- atoms. There are one shorter (3.05 Å) and one longer (3.20 Å) Cs–O bond lengths. There are a spread of Cs–F bond distances ranging from 2.87–3.39 Å. In the second Cs1+ site, Cs1+ is bonded in a 2-coordinate geometry to two O2- and six F1- atoms. There are one shorter (3.10 Å) and one longer (3.12 Å) Cs–O bond lengths. There are a spread of Cs–F bond distances ranging from 2.88–3.50 Å. There are two inequivalent Np4+ sites. In the first Np4+ site, Np4+ is bonded in a 9-coordinate geometry to two O2- and seven F1- atoms. There are one shorter (2.28 Å) and one longer (2.33 Å) Np–O bond lengths. There are a spread of Np–F bond distances ranging from 2.25–2.49 Å. In the second Np4+ site, Np4+ is bonded in a 8-coordinate geometry to two O2- and six F1- atoms. There are one shorter (2.31 Å) and one longer (2.33 Å) Np–O bond lengths. There are a spread of Np–F bond distances ranging from 2.17–2.42 Å. P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Np4+, and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Np4+, and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Np4+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, one Np4+, and one P5+ atom. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Cs1+ and two Np4+ atoms. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Np4+ atoms. In the third F1- site, F1- is bonded in a 2-coordinate geometry to two Cs1+ and two equivalent Np4+ atoms. In the fourth F1- site, F1- is bonded in a 3-coordinate geometry to two equivalent Cs1+ and two Np4+ atoms. In the fifth F1- site, F1- is bonded in a 2-coordinate geometry to two Cs1+ and two equivalent Np4+ atoms. In the sixth F1- site, F1- is bonded in a 3-coordinate geometry to two Cs1+ and one Np4+ atom. In the seventh F1- site, F1- is bonded in a 2-coordinate geometry to two Cs1+ and two equivalent Np4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpPa3 by Materials Project

NpPa3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Pa atoms to form NpPa12 cuboctahedra that share corners with four equivalent NpPa12 cuboctahedra, corners with eight equivalent PaNp4Pa8 cuboctahedra, edges with eight equivalent NpPa12 cuboctahedra, edges with sixteen equivalent PaNp4Pa8 cuboctahedra, faces with four equivalent NpPa12 cuboctahedra, and faces with fourteen PaNp4Pa8 cuboctahedra. There are four shorter (3.06 Å) and eight longer (3.29 Å) Np–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Np and eight Pa atoms to form PaNp4Pa8 cuboctahedra that share corners with twelve equivalent PaNp4Pa8 cuboctahedra, edges with eight equivalent NpPa12 cuboctahedra, edges with sixteen PaNp4Pa8 cuboctahedra, faces with four equivalent NpPa12 cuboctahedra, and faces with fourteen PaNp4Pa8 cuboctahedra. There are four shorter (3.06 Å) and four longer (3.29 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Np and eight equivalent Pa atoms to form distorted PaNp4Pa8 cuboctahedra that share corners with four equivalent PaNp4Pa8 cuboctahedra, corners with eight equivalent NpPa12 cuboctahedra, edges with twenty-four PaNp4Pa8 cuboctahedra, faces with six equivalent NpPa12 cuboctahedra, and faces with twelve PaNp4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpFe3 by Materials Project

NpFe3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Fe atoms to form NpFe12 cuboctahedra that share corners with four equivalent NpFe12 cuboctahedra, corners with eight equivalent FeNp4Fe8 cuboctahedra, edges with eight equivalent NpFe12 cuboctahedra, edges with sixteen equivalent FeNp4Fe8 cuboctahedra, faces with four equivalent NpFe12 cuboctahedra, and faces with fourteen FeNp4Fe8 cuboctahedra. There are eight shorter (2.62 Å) and four longer (2.63 Å) Np–Fe bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to four equivalent Np and eight Fe atoms to form distorted FeNp4Fe8 cuboctahedra that share corners with twelve equivalent FeNp4Fe8 cuboctahedra, edges with eight equivalent NpFe12 cuboctahedra, edges with sixteen FeNp4Fe8 cuboctahedra, faces with four equivalent NpFe12 cuboctahedra, and faces with fourteen FeNp4Fe8 cuboctahedra. There are four shorter (2.62 Å) and four longer (2.63 Å) Fe–Fe bond lengths. In the second Fe site, Fe is bonded to four equivalent Np and eight equivalent Fe atoms to form distorted FeNp4Fe8 cuboctahedra that share corners with four equivalent FeNp4Fe8 cuboctahedra, corners with eight equivalent NpFe12 cuboctahedra, edges with twenty-four FeNp4Fe8 cuboctahedra, faces with six equivalent NpFe12 cuboctahedra, and faces with twelve FeNp4Fe8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpNi5 by Materials Project

NpNi5 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Np is bonded in a distorted hexagonal planar geometry to eighteen Ni atoms. There are six shorter (2.79 Å) and twelve longer (3.12 Å) Np–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Np and eight Ni atoms to form a mixture of edge, face, and corner-sharing NiNp4Ni8 cuboctahedra. There are four shorter (2.41 Å) and four longer (2.42 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded to three equivalent Np and nine Ni atoms to form distorted NiNp3Ni9 cuboctahedra that share corners with twenty-one NiNp4Ni8 cuboctahedra, edges with six equivalent NiNp3Ni9 cuboctahedra, and faces with twenty-three NiNp4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.79 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpMn(OF2)3 by Materials Project

NpMn2O5F8NpOF4 crystallizes in the monoclinic C2 space group. The structure is zero-dimensional and consists of two NpMn2O5F8 clusters and two NpOF4 clusters. In each NpMn2O5F8 cluster, Np5+ is bonded in a 7-coordinate geometry to one O2- and six F1- atoms. The Np–O bond length is 1.80 Å. There are four shorter (2.03 Å) and two longer (2.51 Å) Np–F bond lengths. Mn7+ is bonded in a tetrahedral geometry to two O2- and two F1- atoms. There is one shorter (1.59 Å) and one longer (1.60 Å) Mn–O bond length. Both Mn–F bond lengths are 1.80 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Np5+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Mn7+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Mn7+ atom. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Mn7+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Np5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Np5+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to one Np5+ and one Mn7+ atom. In each NpOF4 cluster, Np5+ is bonded in a distorted square pyramidal geometry to one O2- and four F1- atoms. The Np–O bond length is 1.83 Å. There are two shorter (2.03 Å) and two longer (2.04 Å) Np–F bond lengths. O2- is bonded in a single-bond geometry to one Np5+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Np5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Np5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs(NpSe3)2 by Materials Project

Cs(NpSe3)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Cs1+ is bonded to eight equivalent Se2- atoms to form face-sharing CsSe8 hexagonal bipyramids. All Cs–Se bond lengths are 3.77 Å. Np+5.50+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Np–Se bond distances ranging from 2.89–2.96 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four equivalent Np+5.50+ atoms to form a mixture of distorted corner and edge-sharing SeNp4 trigonal pyramids. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Cs1+, two equivalent Np+5.50+, and two equivalent Se2- atoms. There are one shorter (2.68 Å) and one longer (2.81 Å) Se–Se bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpAg3 by Materials Project

NpAg3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Ag atoms to form NpAg12 cuboctahedra that share corners with four equivalent NpAg12 cuboctahedra, corners with eight equivalent AgNp4Ag8 cuboctahedra, edges with eight equivalent NpAg12 cuboctahedra, edges with sixteen equivalent AgNp4Ag8 cuboctahedra, faces with four equivalent NpAg12 cuboctahedra, and faces with fourteen AgNp4Ag8 cuboctahedra. There are eight shorter (3.11 Å) and four longer (3.20 Å) Np–Ag bond lengths. There are two inequivalent Ag sites. In the first Ag site, Ag is bonded to four equivalent Np and eight Ag atoms to form distorted AgNp4Ag8 cuboctahedra that share corners with twelve equivalent AgNp4Ag8 cuboctahedra, edges with eight equivalent NpAg12 cuboctahedra, edges with sixteen AgNp4Ag8 cuboctahedra, faces with four equivalent NpAg12 cuboctahedra, and faces with fourteen AgNp4Ag8 cuboctahedra. There are four shorter (3.11 Å) and four longer (3.20 Å) Ag–Ag bond lengths. In the second Ag site, Ag is bonded to four equivalent Np and eight equivalent Ag atoms to form AgNp4Ag8 cuboctahedra that share corners with four equivalent AgNp4Ag8 cuboctahedra, corners with eight equivalent NpAg12 cuboctahedra, edges with twenty-four AgNp4Ag8 cuboctahedra, faces with six equivalent NpAg12 cuboctahedra, and faces with twelve AgNp4Ag8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpH28C12(N2O3)6 by Materials Project

Np(CO2)8(CN3H6)4(H2O)2 crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of sixteen guanidinium molecules; eight water molecules; and two Np(CO2)8 ribbons oriented in the (0, 0, 1) direction. In each Np(CO2)8 ribbon, Np4+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Np–O bond distances ranging from 2.40–2.61 Å. There are four inequivalent C+3.33+ sites. In the first C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.27 Å. In the second C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. In the third C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. In the fourth C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Np4+ and one C+3.33+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Np4+ and one C+3.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+3.33+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Np4+ and one C+3.33+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Np4+ and one C+3.33+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Np4+ and one C+3.33+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one C+3.33+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one C+3.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpGa5Rh by Materials Project

NpRhGa5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Np is bonded to twelve Ga atoms to form NpGa12 cuboctahedra that share corners with four equivalent NpGa12 cuboctahedra, faces with four equivalent NpGa12 cuboctahedra, and faces with four equivalent GaNp4Ga8 cuboctahedra. There are eight shorter (2.95 Å) and four longer (3.04 Å) Np–Ga bond lengths. Rh is bonded in a body-centered cubic geometry to eight equivalent Ga atoms. All Rh–Ga bond lengths are 2.55 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 4-coordinate geometry to two equivalent Np, two equivalent Rh, and two equivalent Ga atoms. Both Ga–Ga bond lengths are 2.95 Å. In the second Ga site, Ga is bonded to four equivalent Np and eight equivalent Ga atoms to form GaNp4Ga8 cuboctahedra that share corners with four equivalent GaNp4Ga8 cuboctahedra, faces with four equivalent NpGa12 cuboctahedra, and faces with four equivalent GaNp4Ga8 cuboctahedra.

36 MATERIALS SCIENCE↗