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All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Subsurface cosmogenic and radiogenic production of 42 Ar

Radioactive decays from 42 Ar and its progeny 42 K are potential background sources in large-scale liquid-argon-based neutrino and dark matter experiments. In the atmosphere, 42 Ar is produced primarily by cosmogenic activation on 40 Ar. The use of low radioactivity argon from cosmogenically shielded underground sources can expand the reach and sensitivity of liquid-argon-based rare event searches. We estimate 42 Ar production underground by nuclear reactions induced by natural radioactivity and cosmic-ray muon-induced interactions. At 3,000 mwe, 42 Ar production rate is 1.8×10 -3 atoms per ton of crust per year, 7 orders of magnitude smaller than the 39 Ar production rate at a similar depth in the crust. In conclusion, by comparing the calculated production rate of 42 Ar to that of 39 Ar for which the concentration has been measured in an underground gas sample, we estimate the activity of 42 Ar in gas extracted from 3,000 mwe depth to be less than two decays per ton of argon per year.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2022

Evaluation of cosmogenic production of 39 Ar and 42 Ar for rare-event physics using underground argon

Underground argon (UAr) with lower cosmogenic activities of 39 Ar and 42 Ar has been planned as a detector in detecting scintillation light and charge collection using time projection chambers for dark matter searches and as a veto detector in suppressing backgrounds for neutrinoless double beta decay (0$vββ$ ) experiments. Long-lived radioactive isotopes, 39 Ar and 42 Ar, can also be produced on the surface when UAr is pumped out from a deep well. Understanding the production of long-lived isotopes in Ar is important for utilizing UAr for dark matter and 0$vββ$ experiments in terms of its production, transportation, and storage. Ar exposure to cosmic rays at sea-level is simulated using Geant4 for a given cosmic ray muon, neutron, and proton energy spectrum. Here we report the simulated cosmogenic production rates of 39 Ar, 42 Ar, and other long-lived isotopes at sea-level from fast neutrons, high energy muons, and high energy protons. Total production rates of 938.53/kg Ar day and 5.81 × 10 -3 /kg Ar day for 39 Ar and 42 Ar are found from our simulation. Utilizing these production rates, we set a time limit of 954 days constrained by the production of 39 Ar for UAr to be on the surface before it compromises the sensitivity for a dark matter experiment. Similarly, a time limit of 1702 days constrained by the production of 42 Ar is found for a 0$vββ$ experiment.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Improved thermonuclear rate of 42 Ti( p , γ ) 43 V and its astrophysical implication in the rp process

Context. Accurate 42 Ti(p,γ) 43 V reaction rates are crucial for understanding the nucleosynthesis path of the rapid capture process (rp process) that occurs in X-ray bursts. Aims. We aim to improve the thermonuclear rates of 42 Ti(p,γ) 43 V based on more complete resonance information and a more accurate direct component, together with the recently released nuclear masses data. We also explore the impact of the newly obtained rates on the rp process. Methods. We reevaluated the reaction rate of 42 Ti(p,γ) 43 V by the sum of the isolated resonance contribution instead of the Hauser-Feshbach statistical model. We used a Monte Carlo method to derive the associated uncertainties of new rates. The nucleosynthesis simulations were performed via the NuGrid post-processing code ppn. Results. The new rates differ from previous estimations due to the use of a series of updated resonance parameters and a direct S factor. Compared with the previous results from the Hauser-Feshbach statistical model, which assumes compound nucleus 43 V with a sufficiently high-level density in the energy region of astrophysical interest, large differences exist over the entire temperature region of rp-process interest, up to two orders of magnitude. We consistently calculated the photodisintegration rate using our new nuclear masses via the detailed balance principle, and found the discrepancies among the different reverse rates are much larger than those for the forward rate, up to ten orders of magnitude at the temperature of 10 8 K. Using a trajectory with a peak temperature of 1.95×10 9 K, we performed the rp-process nucleosynthesis simulations to investigate the impact of the new rates. Our calculations show that the adoption of the new forward and reverse rates result in abundance variations for Sc and Ca of 128% and 49%, respectively, compared to the variations for the statistical model rates. On the other hand, the overall abundance pattern is not significantly affected. The results of using new rates also confirm that the rp-process path does not bypass the isotope 43 V. Conclusions. Our study found that the Hauser-Feshbach statistical model is inappropriate to the reaction rate evaluation for 42 Ti(p,γ) 43 V. The adoption of the new rates confirms that the reaction path of 42 Ti(p,γ) 43 V(p,γ) 44 Cr(β + ) 44 V is a key branch of the rp process in X-ray bursts.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Cross‐Cultural Validation of the Binge Eating Disorder Screener‐7 ( BEDS ‐7) Across 42 Countries

ABSTRACT Objective This study aimed to evaluate the reliability and validity of the Binge Eating Disorder Screener‐7 (BEDS‐7) across 42 countries and 26 languages, assessing its reliability and validity as a screening tool for binge‐eating disorder (BED) in diverse cultural contexts. Specifically, it sought to enhance early recognition of BED symptoms in primary care settings globally, contributing to a standardized framework for assessing BED. Method The International Sex Survey, a cross‐sectional online study, was conducted in 42 countries and 26 languages. A diverse community sample of 82,243 participants, aged 18 years or older, completed the BEDS‐7 and measures of sexuality, mental health, substance use, and sociodemographic characteristics. Confirmatory factor analyses and tests of measurement invariance were employed to evaluate the reliability and validity of the BEDS‐7 across languages, countries, genders, and sexual orientations. Results The BEDS‐7 demonstrated scalar factorial invariance across languages and countries, indicating consistent factor loadings and item intercepts. In contrast, the screener showed residual invariance across gender and sexual orientation groups, supporting its robustness across these demographics. Kruskal–Wallis tests revealed significant differences in BED symptoms across languages, countries, genders, and sexual orientations, with the highest BED scores observed among queer, pansexual, and gender‐diverse individuals. The BEDS‐7 also demonstrated adequate reliability (Cronbach's alpha > 0.80) and moderate criterion validity. Discussion The findings provide further evidence of the reliability and validity of the BEDS‐7 as a potential screening tool for identifying probable cases of BED globally, facilitating early intervention in primary care settings.

Gewirtz‐Meydan, Ateret [School of Social Work, Fac↗
DOE OSTI2025

Determination of proton and neutron contributions to the 0$^+_{𝑔⁡𝑠}$ → 2$^+_{1}$ excitations in 42 Si and 44 S using inelastic proton scattering in inverse kinematics and intermediate-energy Coulomb excitation

Here, we have measured the 0$^+_{𝑔⁡𝑠}$ → 2$^+_1$ transition in the neutron-rich 𝑁 = 28 isotope 42 Si using the probes of intermediate-energy Coulomb excitation and inelastic proton scattering in inverse kinematics at the Facility for Rare Isotope Beams with beam particle rates of ≈ 5 particles/s. The results of these two measurements allowed us to determine 𝑀 𝑛 /𝑀 𝑝 , the ratio of the neutron and proton transition matrix elements for the 0$^+_{𝑔⁡𝑠}$ → 2$^+_1$ transition. In addition, we have measured the 0$^+_{𝑔⁡𝑠}$ → 2$^+_1$ transition in the isotone 44 S using inverse kinematics inelastic proton scattering. By comparing the 44 S proton-scattering result with a recent intermediate-energy Coulomb excitation result on the same transition, we were able to determine 𝑀 𝑛 /𝑀 𝑝 for the 0$^+_{𝑔⁡𝑠}$ → 2$^+_1$ transition in this nucleus as well. This work strengthens the evidence that 42 Si has a stable quadrupole deformation in its ground state and that 44 S does not. Both conclusions are further supported by shell-model calculations carried out with the FSU interaction.

39 ≤ A ≤ 58↗
DOE OSTI2022

Federal Energy Savings Performance Contracts Frequently Asked Questions on the Scope of 42 U.S.C. § 8287 et. seq.

The U.S. Department of Energy's Federal Energy Management Program (FEMP) is issuing this document to provide clarifications and guidance on issues commonly raised regarding the scope of 42 U.S.C. § 8287 et seq. This document is intended to supplement FEMP's extensive collection of materials that are available to assist federal agencies execute successful energy savings performance contracting (ESPC) projects.

42 U.S.C. § 8287 et. seq.↗
DOE OSTI2025

Au 76 (SC 6 H 4 - p -CH 3 ) 42 Square Quantum Platelet: One-Dimensional Growth of Quantum Rods Turns 90 Degrees

The growth pattern of atomically precise nanoclusters (NCs) is of fundamental interest, and the structural effect on their photoluminescence (PL) is important owing to their PL in the second near-infrared (NIR-II) range (900–1700 nm optoelectronically or 1000–1700 nm biologically) that holds great promise for optoelectronic and biomedical applications. Because of the small energy gaps required for NIR-II emission, the PL performance of NIR-II luminophores is largely limited by nonradiative processes. In this work, we discovered a Au 76 (p-MBT) 42 (Au 76 ) (p-MBTH = p-methylbenzenethiol) nanocluster featuring a face-centered cubic (fcc) core in a square shape (edge length: 1 nm). This square quantum platelet can be viewed as a side-facet (010) growth of the Au 52 (p-MBT) 32 (Au 52 ) rod, as opposed to the (001) facet growth. We found that Au 76 exhibits bright emission centered at 970 nm with a PL quantum yield (PLQY) of 30% in solution under ambient conditions, which can be further enhanced to 40% when the solution is deaerated. X-ray crystallography analysis coupled with time-resolved spectroscopy revealed that the nearly doubled PLQY compared to Au 52 (18.3%) was resulted from shorter Au–Au bond lengths in Au 76 (average 2.835 Å) than that in Au 52 (3.04 Å). This work provides important insights into the design of highly luminescent NCs, which are promising for photovoltaics, photocatalysis, and optoelectronic applications.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Quadrupole collectivity in the neutron-rich sulfur isotopes 38,40,42,44 S

Electromagnetic transition strengths in the even-even neutron-rich sulfur isotopes 38,40,42,44 S were measured using intermediate-energy Coulomb excitation at the National Superconducting Cyclotron Laboratory. By utilizing the sensitivity of the experimental technique to E2 excitations from the ground state, the evolution of the pattern of B(E2) strengths to several low-lying 2 + states was investigated at Z = 16 from near stability to the N = 28 island of inversion. The experimental results allowed a detailed comparison with predictions from shell-model calculations using the SDPF-MU Hamiltonian, which was designed to describe collectivity in this region of the nuclear chart. While the shell-model calculations succeeded in modeling transition strengths at N = 22, 24, 26, the experimental B(E2; $0$ $^{+}_{1}$ → $2$ $^{+}_{1}$) at N = 28 was smaller than the predicted value by about a factor of 2, similar to previous observations for chlorine and argon isotopes around N = 28. The dependence of this overprediction by theory on the choice of effective charges was explored.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Structure of 43 P and 42 Si in a two-level shape-coexistence model

Exclusive cross sections for the 43 P(-1p) 42 Si reaction to the lowest 0 + and 2 + states, measured at NSCL with GRETINA and the S800, are interpreted in terms of a two-level mixing (collective) model of oblate and prolate co-existing shapes. Here, using the formalism developed for deformed nuclei we calculate the spectroscopic amplitudes and exclusive cross-sections in the strong coupling limit, where for 43 P the schematic wavefunction includes the coupling of the Nilsson [211] 1/2 proton orbit. Good agreement with the experimental data is obtained when the amplitude of the oblate configuration is larger or equal than 80%, suggesting that both nuclei are predominantly oblate, in line with theoretical expectations. Model predictions for excitation energies and electromagnetic observables, that could motivate further studies of both nuclei, are also presented.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

Wave climate and energy resources in American Samoa from a 42-year high-resolution hindcast

Here, this paper presents an analysis of the wave climate and a characterization of the wave energy resources in American Samoa, a U.S. territory covering seven south central Pacific islands and atolls. A numerical wave model based on WAVEWATCH III® and unstructured SWAN was developed, validated, and executed for 1979–2020 to generate a hindcast dataset suitable for resource characterization. Model-data comparisons were performed with measurements collected in situ and from satellite-based altimeters. The model was found to perform well with a bias in significant wave height of -0.14 m and -0.06 m against buoy and altimeters, respectively. The multimodal sea state of American Samoa is investigated by identifying the sources of energy reaching the islands and partitioning the wave spectrum accordingly. The wave resources characterization follows the International Electrotechnical Commission Technical Specifications to be compatible with studies performed for other U.S. regions. The average omnidirectional wave power at 2 km from shore around Tutuila, the main island of American Samoa, is 14 kW/m. Locations east and west of the islands have a more consistent resource throughout the year because the northwest and southwest swells that are dominant during different seasons complement each other.

16 TIDAL AND WAVE POWER↗
DOE OSTI2023

Wave climate and energy resources in the Mariana Islands from a 42-year high-resolution hindcast

We report a high-resolution wave hindcast from 1979 to 2020 was developed for Guam and the Commonwealth of the Northern Mariana Islands, which are influenced by mesoscale and synoptic weather systems from the western Pacific Rim to the Central Pacific. The spectral wave modeling utilized structured global and unstructured regional grids with improved resolution in nearshore waters, where wave resources development is most feasible. The hindcast demonstrates its capability in capturing multi-modal seas through reproduction of bulk and partitioned wave parameters derived from altimetry and buoy measurements. The local wave climate is influenced by the year-round trade winds and tropical cyclones as well as seasonal monsoons, frontal systems, and mid-latitude high- and low-pressure systems. The strong intra-annual variation of the significant wave height and power flux reflects transitions between local and distant weather systems, which account for the diverse wave conditions comprised of short-period wind waves, intermediate-period seas, and long-period swells around the islands. Among the Pacific island regions, spectral partitioning is particularly important for describing the dominant wave components by period and direction with pertinent information conducive to energy resources characterization and coastal zone management in the Mariana Islands.

16 TIDAL AND WAVE POWER↗
DOE OSTI2021

In-beam γ-ray spectroscopy of 37–42 P

The level schemes of the neutron-rich 37-42 P isotopes are investigated via in-beam gamma-ray spectroscopy following the fragmentation of a 45 Cl projectile beam at intermediate beam energies. Information on gamma-gamma coincidence relationships complemented by comparisons to shell-model calculations in the sd-pf model space were used to construct excitation level schemes for these neutron-rich nuclei. For the odd-mass 37,39 P isotopes, a level scheme is presented that appears essentially complete at low energies and exhausts the states predicted by the SDPF-MU shell-model Hamiltonian. In conclusion, simple Nilsson configurations are proposed for the low-lying excited states of 38,39,40,41 P from an analysis of the E2 transition matrix elements and moments calculated within the shell model.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Genome Sequences of 42 Bacteria Isolated from Sorghum bicolor Roots

Forty-two bacterial strains were isolated from root samples of Sorghum bicolor. The strains spanned 17 genera, including Dechloromonas, Duganella, Dyella, Flavobacterium, Herbaspirillum, Lutibacter, Mucilaginibacter, Novosphingobium, Paraburkholderia, Pedobacter, Pleomorphomonas, Rhizobacter, Rhizobium, Rhizomicrobium, Rugamonas, Variovorax, and Xanthobacter. Their whole-genome sequences revealed diverse metabolic processes, including biological nitrogen fixation, in sorghum root microbiota.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Adenosine A2A Receptor Up-Regulation Pre-Dates Deficits of Synaptic Plasticity and of Memory in Mice Exposed to Aβ1–42 to Model Early Alzheimer’s Disease

The intracerebroventricular (icv) injection of amyloid peptides (Aβ) models Alzheimer’s disease (AD) in mice, as typified by the onset within 15 days of deficits of memory and of hippocampal long-term potentiation (LTP) that are prevented by the blockade of adenosine A2A receptors (A2AR). Since A2AR overfunction is sufficient to trigger memory deficits, we tested if A2AR were upregulated in hippocampal synapses before the onset of memory deficits to support the hypothesis that A2AR overfunction could be a trigger of AD. Six to eight days after Aβ-icv injection, mice displayed no alterations of hippocampal dependent memory; however, they presented an increased excitability of hippocampal synapses, a slight increase in LTP magnitude in Schaffer fiber-CA1 pyramid synapses and an increased density of A2AR in hippocampal synapses. A2AR blockade with SCH58261 (50 nM) normalized excitability and LTP in hippocampal slices from mice sacrificed 7–8 days after Aβ-icv injection. Fifteen days after Aβ-icv injection, mice displayed evident deficits of hippocampal-dependent memory deterioration, with reduced hippocampal CA1 LTP but no hyperexcitability and a sustained increase in synaptic A2AR, which blockade restored LTP magnitude. This shows that the upregulation of synaptic A2AR precedes the onset of deterioration of memory and of hippocampal synaptic plasticity, supporting the hypothesis that the overfunction of synaptic A2AR could be a trigger of memory deterioration in AD.

Lopes, Cátia R.↗
DOE OSTI2020

Materials Data on Mo15N16 by Materials Project

Mo15N16 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are fifteen inequivalent Mo+3.20+ sites. In the first Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 43–47°. There are a spread of Mo–N bond distances ranging from 2.14–2.20 Å. In the second Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of Mo–N bond distances ranging from 2.15–2.21 Å. In the third Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of Mo–N bond distances ranging from 2.16–2.21 Å. In the fourth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 43–47°. There are a spread of Mo–N bond distances ranging from 2.16–2.19 Å. In the fifth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 41–49°. There are a spread of Mo–N bond distances ranging from 2.11–2.22 Å. In the sixth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 43–46°. There are a spread of Mo–N bond distances ranging from 2.09–2.29 Å. In the seventh Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There are a spread of Mo–N bond distances ranging from 2.16–2.22 Å. In the eighth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 41–50°. There are a spread of Mo–N bond distances ranging from 2.08–2.28 Å. In the ninth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of Mo–N bond distances ranging from 2.11–2.23 Å. In the tenth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 44–47°. There are a spread of Mo–N bond distances ranging from 2.16–2.24 Å. In the eleventh Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There are a spread of Mo–N bond distances ranging from 2.14–2.21 Å. In the twelfth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 41–50°. There are a spread of Mo–N bond distances ranging from 2.13–2.22 Å. In the thirteenth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of Mo–N bond distances ranging from 2.15–2.23 Å. In the fourteenth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There are a spread of Mo–N bond distances ranging from 2.14–2.22 Å. In the fifteenth Mo+3.20+ site, Mo+3.20+ is bonded to six N3- atoms to form a mixture of face, edge, and corner-sharing MoN6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There are a spread of Mo–N bond distances ranging from 2.14–2.19 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to five Mo+3.20+ atoms to form distorted NMo5 trigonal bipyramids that share corners with five NMo6 pentagonal pyramids, corners with two NMo5 trigonal bipyramids, and edges with seven NMo6 pentagonal pyramids. In the second N3- site, N3- is bonded to five Mo+3.20+ atoms to form distorted NMo5 trigonal bipyramids that share corners with three equivalent NMo6 pentagonal pyramids, corners with two NMo5 trigonal bipyramids, and edges with eight NMo6 pentagonal pyramids. In the third N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with three equivalent NMo6 pentagonal pyramids, corners with three equivalent NMo5 trigonal bipyramids, edges with eight NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the fourth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with four NMo6 pentagonal pyramids, edges with seven NMo6 pentagonal pyramids, and edges with four NMo5 trigonal bipyramids. In the fifth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with four NMo6 pentagonal pyramids, corners with two equivalent NMo5 trigonal bipyramids, edges with seven NMo6 pentagonal pyramids, and an edgeedge with one NMo5 trigonal bipyramid. In the sixth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with three equivalent NMo6 pentagonal pyramids, edges with eight NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the seventh N3- site, N3- is bonded in a 5-coordinate geometry to five Mo+3.20+ atoms. In the eighth N3- site, N3- is bonded in a 5-coordinate geometry to five Mo+3.20+ atoms. In the ninth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with five NMo6 pentagonal pyramids, edges with seven NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the tenth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with five NMo6 pentagonal pyramids, a cornercorner with one NMo5 trigonal bipyramid, edges with seven NMo6 pentagonal pyramids, and edges with three NMo5 trigonal bipyramids. In the eleventh N3- site, N3- is bonded to five Mo+3.20+ atoms to form distorted NMo5 trigonal bipyramids that share corners with three equivalent NMo6 pentagonal pyramids, corners with two NMo5 trigonal bipyramids, and edges with eight NMo6 pentagonal pyramids. In the twelfth N3- site, N3- is bonded in a 5-coordinate geometry to five Mo+3.20+ atoms. In the thirteenth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with three equivalent NMo6 pentagonal pyramids, edges with eight NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the fourteenth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with three equivalent NMo6 pentagonal pyramids, corners with three equivalent NMo5 trigonal bipyramids, edges with eight NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the fifteenth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with four NMo6 pentagonal pyramids, edges with seven NMo6 pentagonal pyramids, and edges with two NMo5 trigonal bipyramids. In the sixteenth N3- site, N3- is bonded to six Mo+3.20+ atoms to form distorted NMo6 pentagonal pyramids that share corners with four NMo6 pentagonal pyramids, corners with two equivalent NMo5 trigonal bipyramids, edges with seven NMo6 pentagonal pyramids, and edges with three NMo5 trigonal bipyramids.

36 MATERIALS SCIENCE↗