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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

NIRDye 812: A molecular platform tailored for multimodal bioimaging applications of targeted fluorescence- and photoacoustic-guided surgery

The primary treatment for malignant tumors remains to be surgical removal of the diseased tissue. The presence or absence of residual diseased tissue at the tumor margin is the strongest predictor of postoperative prognosis and recurrence. Accordingly, reliance on the ability of surgeons to visually distinguish diseased tissue from healthy tissue unambiguously in real time is crucial. Near infrared-I (NIRsingle bondI) fluorescence-emitting targeting biomolecular constructs such as anticancer antibody-fluorophore conjugates, namely cetuximab-IRDye® 800CW (CTB-IRDye® 800CW), are FDA-approved for clinical trial usage in the fluorescence-guided resection of diseased tissue due to affording improved direct visualization of tumor tissue when compared to the use of either the unaided eye under standard white light illumination (WLI) surgical techniques or non-targeting fluorophores. Unfortunately, though helpful, CTB-IRDye® 800CW affords limited (i) identification of diseased tissue and (ii) tumor margin delineation, because the immunoconjugate generates suboptimal tumor-to-background ratios (TBRs) as a result of its spectral/photophysical profiles poorly aligning with the fixed optical windows of pre-/clinical setups. As such, CTB-IRDye® 800CW is more prone to affording incomplete resection compared to if TBRs were higher due to otherwise. Here, to aid in accurately identifying deep-seated diseased tissue, photoacoustic (PA) tomography has been implemented alongside CTB-IRDye® 800CW to achieve PA signals that could result in higher TBRs. However, in clinical trial practice, using IRDye® 800CW for PA imaging also yields subpar TBRs due to it affording low PA signals. To overcome such limitations, we developed NIRDye 812, a structurally-modified topological equivalent of IRDye® 800CW, to confer it the capability to yield both higher TBRs and superior PA signal than that of the equivalent CTB-conjugate and fluorophore IRDye® 800CW itself, respectively. To do so, we substituted the oxygen atom at its meso-position with a sulfur atom. CTB-NIRDye 812 demonstrated a red-shifted absorption wavelength at 796 nm and a peak NIR-I fluorescence emission wavelength at 820 nm, which better dovetails with the fixed windows of preinstalled fixed emission filters within commercial pre-/clinical NIR-I fluorescence imaging instruments. Overall, CTB-NIRDye 812 provided a ~ 2-fold increase in TBRs compared to those of CTB-IRDye® 800CW in vivo. Also, NIRDye 812 displayed an ~60% higher PA signal than that of IRDye® 800CW. Collectively, we achieved our goal of improving upon the spectral/photophysical and PA properties of IRDye® 800CW via introducing a subtle modification to its electronic core such that its CTB immunoconjugate could potentially allow for fast track or breakthrough designation by the FDA due to its near-identical structure displaying considerably improved efficacy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Synthesis and characterization of imidazolium-mediated Tröger's base containing poly(amide)-ionenes and composites with ionic liquids for CO 2 separation membranes

Considerable attention has been given to polymeric membranes either containing, or built from, ionic liquids (ILs) in gas separation processes due to their selective separation of CO 2 molecules. Achieving high-performance CO 2 separation membranes with enhanced permeability and selectivity relies mainly on rationally designing the molecular substructure and molecular composition of the polymer matrix. In this work, we have exclusively explored a facile synthetic route to incorporate aromatic amide linkages onto an ionene backbone derived from imidazolium-mediated Tröger's base moieties, yielding a novel rigid polyamide-ionene material (“Im-TB-PA ionene”). We have optimized two novel Im-TB-PA ionene polymers via Menshutkin reactions between N,N'-(1,4-phenylene)bis(4-(chloromethyl)benzamide) and equimolar amounts of two isomeric diimidazole-functionalized Tröger's base monomers with ‘ortho’ or ‘para’ regiochemistry. The two resulting Im-TB(o&p)-PA ionenes exhibited high molecular weights and excellent solubilities in polar organic solvents, serving homogeneous and mechanically stable blend membranes with “free” ILs. The structural and physical properties, as well as the gas separation behaviors of both the Im-TB(o&p)-PA ionenes and their IL composite counterparts ([Im-TB(o&p)-PA] + [IL]), were further extensively investigated. The membrane with an optimal composition and polymer architecture ([Im-TB(o)-PA] + [IL]) exhibited outstanding permselectivites for CO 2 /CH 4 (46.73), CO 2 /N 2 (51.74), and CO 2 /H 2 (4.38) gas pairs together with the best CO 2 permeability of 47.2 barrer. Altogether, this study provides a promising strategy to explore the benefits of Im-TB-PA ionenes to separate CO 2 from flue gas, natural gas, and syngas streams, while opening new possibilities in polymer design with strong candidate materials for other practical applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Millions of Small Pressure Cycles Drive Damage in Cracked Solar Cells

Here, we applied time-varying air pressure to a PV module containing newly cracked cells. The test used a new dynamic mechanical acceleration (DMX) apparatus. We applied pressure cycles similar to natural, wind-driven cycles. Compared to standard dynamic mechanical load (DML) tests, we applied much lower pressure (10 Pa to 300 Pa RMS) and many more cycles (one million at each of four pressure levels). We present a case study on a single cell in a commercial module. We monitored electrical continuity loss across cracks using electroluminescence (EL) imaging. 10 Pa pressure cycles caused negligible change. 30 Pa pressure cycles caused permanent damage that continued worsening even after tens of thousands of cycles. After one million 30 Pa cycles, a series of 100 Pa cycles still caused new, permanent damage to existing cracks. 300 Pa cycles caused further worsening and introduced new cracks.

14 SOLAR ENERGY↗
DOE OSTI2024

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI-GC–MS and LC-HRMS in official OPCW proficiency test matrices

Pinacolyl alcohol (PA), a key forensic marker for the nerve agent Soman (GD), is a particularly difficult analyte to detect by various analytical methods. In this work, we have explored the reaction between PA and 1,1'-carbonyldiimidazole (CDI) to yield pinacolyl 1H-imidazole-1-carboxylate (PIC), a product that can be conveniently detected by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Regarding its GC–MS profile, this new carbamate derivative of PA possesses favorable chromatographic features such as a sharp peak and a longer retention time (RT = 16.62 min) relative to PA (broad peak and short retention time, RT = 4.1 min). Additionally, the derivative can also be detected by LC-HRMS, providing an avenue for the analysis of this chemical using this technique where PA is virtually undetectable unless present in large concentrations. From a forensic science standpoint, detection of this low molecular weight alcohol signals the past or latent presence of the nerve agent Soman (GD) in a given matrix (i.e., environmental or biological). The efficiency of the protocol was tested separately in the analysis and detection of PA by EI-GC–MS and LC-HRMS when present at a 10 μg/mL in a soil matrix featured in the 44th PT and in a glycerol-rich liquid matrix featured in the 48th Official Organization for the Prohibition of Chemical Weapons (OPCW) Proficiency Test when present at a 5 μg/mL concentration. In both scenarios, PA was successfully transformed into PIC, establishing the protocol as an additional tool for the analysis of this unnatural and unique nerve agent marker by GC–MS and LC-HRMS.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Annual Status Report (FY 2020): Performance Assessment for the Disposal of Low Level Waste in the 200 East Area Burial Grounds

This annual review provides the projected dose estimates of radionuclide inventories disposed in the 200 East Area Low-Level Waste Burial Grounds (LLBGs) since September 26, 1988. These estimates are calculated using the original dose methodology developed in the performance assessment (PA) analysis (WHC-SD-WM-TI-730). The estimates are compared with requirements of DOE O 435.1 Chg 1 and performance objectives defined in companion documents DOE M 435.1-1 Chg 1and DOE-STD-5002-2017). All performance objectives are currently satisfied, and operational waste acceptance criteria (HNF-EP-0063) and waste acceptance practices continue to be sufficient to maintain compliance with performance objectives. Inventory estimates and associated dose estimates from future waste disposal actions are unchanged from previous years’ evaluations that indicate potential impacts well below performance objectives; therefore, future compliance with DOE O 435.1 Chg 1 is expected. A new PA study was initiated in fiscal year (FY) 2019 for evaluation of active disposal sites within the 200 East and 200 West Areas (Trench 94 in 200 East; Trenches 31 and 34 in 200 West) due to extended time elapsing between the current annual status report and the original PA for the active disposal sites. The new PA for the active disposal sites is expected to be completed in FY 2021. Within the active burial grounds in the 200 East Area, low-level waste and mixed low-level waste will continue to be disposed of in the dedicated U.S. Navy reactor compartment trench at the 218-E-12B Burial Ground (Trench 94). During this reporting period (FY 2020, from October 1, 2019, through September 30, 2020), two reactor compartments were disposed in Trench 94. Results from sorption experiments are summarized for this reporting period to quantify the efficacy of concrete waste forms in retaining key radionuclides (e.g., technetium-99 and iodine-129). The test durations ranged from 1 to 3 months. Continued groundwater monitoring of the 200 East Area LLBGs indicates no groundwater contamination due to LLBG waste. Current assumptions about future land use at the Hanford Site are consistent with PA analysis1 assumptions of a post-closure facility that will not be degraded by human activity. The LLBGs are located in an area identified for waste management and containment of residual contamination. This area will remain after final environmental remediation and the proposed shrinkage of Hanford Site boundaries to small sections within the 200 East and 200 West Areas in the Central Plateau (DOE/EIS-0391). The current closure plan for the LLBGs (DOE/RL-2000-707) estimates that the 200 East LLBGs will be closed in the 2050 timeframe. The Disposal Authorization Statement, other technical basis documents, and the radioactive waste management basis are of continued adequacy to meet the performance objectives of DOE O 435.1 Chg 1. Overall, there are no substantive changes to primary PA assumptions nor the PA analysis conclusion; therefore, compliance with DOE O 435.1 Chg 1 and the Disposal Authorization Statement is maintained.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Performance Assessment for the Disposal of Low-Level Waste in the 200 West Area Burial Grounds (Annual Status Report FY 2022)

This annual review provides the projected dose estimates of radionuclide inventories disposed in the active 200 West Area Low-Level Waste Burial Grounds (LLBGs) since September 26, 1988. These estimates are calculated using the original dose methodology developed in the performance assessment (PA) analysis (WHC-EP-0645). The estimates are compared with the performance objectives defined in U.S. Department of Energy requirements (DOE O 435.1 and its companion documents DOE M 435.1-1 and DOE-STD-5002-2017). All performance objectives are currently satisfied, and operational waste acceptance criteria (HNF-EP-0063) and waste acceptance practices continue to be sufficient to maintain compliance with performance objectives. Inventory estimates and associated dose estimates from future waste disposal actions are unchanged from previous years’ evaluations that indicate potential impacts well below performance objectives; therefore, future compliance with DOE O 435.1 is expected. Within the active burial grounds, low-level and mixed low-level waste currently may be disposed only in two lined trenches in the 218-W-5 Burial Ground (Trenches 31 and 34) until they are either filled or a decision is made to close these trenches. Some mixed low-level waste is also disposed at the Environmental Restoration Disposal Facility in the 200 West Area (which is covered under a separate PA). During this (fiscal year 2022) reporting period (October 1, 2021, through September 30, 2022), waste was disposed to the 200 West Area LLBGs. Continued groundwater monitoring of the 200 West Area LLBGs indicates no groundwater contamination due to LLBG waste. Current assumptions about future land use at the Hanford Site are consistent with PA analysis assumptions of a postclosure facility that will not be degraded by human activity. The LLBGs are in an area identified for waste management and containment of residual contamination (DOE/EIS-0391). The current closure plan for the LLBGs (DOE/RL-2000-70) estimates that the 200 West LLBGs will be closed in the 2050 timeframe. The Disposal Authorization Statement, other technical basis documents, and the radioactive waste management basis are of continued adequacy to meet the performance objectives of DOE O 435.1. Overall, there are no substantive changes to primary PA assumptions and no changes to the PA analysis conclusion; therefore, compliance with DOE O 435.1 and the Disposal Authorization Statement is maintained. A new PA to evaluate the long-term impacts of three disposal trenches that are currently active within the 200 East and 200 West Areas (Trench 94 in the 200 East Area and Trenches 31 and 34 in the 200 West Area) was initiated in fiscal year 2019 and completed in fiscal year 2022. Corrective actions addressing 3 key issues and 31 secondary issues identified during the review process were developed and submitted to the Low-Level Waste Disposal Facility Federal Review Group Co-Chairs for review and approval. This PA provides additional technical basis for the continued adequacy of the existing Operating Disposal Authorization Statement.

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

Calcium Sulfate and Calcium Carbonate Scaling of Thin-Film Composite Polyamide Reverse Osmosis Membranes with Surface-Tethered Polyacrylic Acid Chains

The gypsum and calcite scaling propensities of the thin-film composite polyamide (PA-TFC) reverse osmosis (RO) membrane, modified with a tethered surface layer of polyacrylic acid (PAA) chains, was evaluated and compared to the scaling of selected commercial RO membranes. The tethered PAA layer was synthesized onto a commercial polyamide membrane (i.e., base-PA) via atmospheric pressure plasma-induced graft polymerization (APPIGP). The PAA nano-structured (SNS) base-PA membrane (SNS-PAA-PA) was scaled to a lesser degree, as quantified by a lower permeate flux decline and surface imaging, relative to the tested commercial membranes (Dow SW30, Toray SWRO, and BWRO). The cleaning of gypsum-scaled membranes with D.I. water flushing achieved 100% water permeability recovery for both the SNS-PAA-PA and Dow SW30 membranes, relative to 92–98% permeability restoration for the Toray membranes. The calcium carbonate scaling of SNS-PAA-PA membranes was also lower relative to the commercial membranes, but permeability recovery after D.I. water cleaning was somewhat lower (94%) but consistent with the level of surface scale coverage. In contrast, the calcite and gypsum-scaled membrane areas of the commercial membranes post-cleaning were significantly higher than for the SNS-PAA-PA membrane but with 100% permeability recovery, suggesting the potential for membrane damage when mineral scaling is severe.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Molecular insights into the structure-property relationships of 3D printed polyamide reverse-osmosis membrane for desalination

3D-printing is an emerging method for manufacturing polyamide (PA) reserve osmosis (RO) membranes for water treatment and desalination, which can precisely control membrane structural properties, such as thickness, roughness, and resolution. However, the synthesis-structure (i.e., degree of cross-linking (DC), m-phenylenediamine/trimesoyl chloride (MPD/TMC) ratio, and membrane thickness) to property (permeability and water-salt selectivity) relationships for these membranes has not been well understood. At the same time, a microscopic understanding of the physical mechanism of water and salt transport is needed to guide the design of high-performance 3D-printed membranes and improve the printing efficiency. Furthermore, the atomic-scale transport features and energetics of water and salt ions are studied at high pressure for the 3D-printed PA RO membranes with the different DCs and MPD/TMC ratios through non-equilibrium molecular dynamics (NEMD) simulations. Factoring in membrane structure properties, rejection ratio of salt ions and pressure-dependent water flux, 3D-printed PA membranes having an MPD/TMC ratio of 3.0:2.0 and a DC between 80%~90% attains ideal performance: high water flux, high rejection of salt ions, and excellent structural integrity. Mechanistically, water permeability for highly cross-linked PA RO membranes depends on the temporary on-and-off channels that allow water molecules to jump from one cavity to another at high pressure. In addition, higher pressures cause rapid compaction of PA membranes’ free volume and membrane thickness. Membrane failure at high pressure is determined by the DC and MPD/TMC ratios-dependent compressive yield strength. In short, these findings provide physical insights for optimizing existing PA membranes and designing next-generation desalination membranes at the molecular level.

3D-printed PA RO membrane↗
DOE OSTI2020

Materials Data on PaCl2O by Materials Project

PaOCl2 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are three inequivalent Pa4+ sites. In the first Pa4+ site, Pa4+ is bonded in a 7-coordinate geometry to three O2- and four Cl1- atoms. There are two shorter (2.23 Å) and one longer (2.26 Å) Pa–O bond lengths. There are two shorter (2.79 Å) and two longer (2.81 Å) Pa–Cl bond lengths. In the second Pa4+ site, Pa4+ is bonded in a 9-coordinate geometry to four O2- and five Cl1- atoms. There are a spread of Pa–O bond distances ranging from 2.29–2.41 Å. There are a spread of Pa–Cl bond distances ranging from 2.84–3.06 Å. In the third Pa4+ site, Pa4+ is bonded in a 8-coordinate geometry to three O2- and five Cl1- atoms. There are two shorter (2.16 Å) and one longer (2.34 Å) Pa–O bond lengths. There are a spread of Pa–Cl bond distances ranging from 2.78–3.08 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Pa4+ atoms to form distorted corner-sharing OPa4 tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Pa4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Pa4+ atoms. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two Pa4+ atoms. In the second Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two equivalent Pa4+ atoms. In the third Cl1- site, Cl1- is bonded in a 3-coordinate geometry to three Pa4+ atoms. In the fourth Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to two equivalent Pa4+ atoms. In the fifth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to three Pa4+ atoms. In the sixth Cl1- site, Cl1- is bonded in a bent 150 degrees geometry to two Pa4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Si by Materials Project

Pa3Si is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Si atoms to form distorted PaPa8Si4 cuboctahedra that share corners with twelve equivalent PaPa8Si4 cuboctahedra, edges with eight equivalent SiPa12 cuboctahedra, edges with sixteen equivalent PaPa8Si4 cuboctahedra, faces with four equivalent SiPa12 cuboctahedra, and faces with fourteen equivalent PaPa8Si4 cuboctahedra. All Pa–Pa bond lengths are 3.14 Å. All Pa–Si bond lengths are 3.14 Å. Si is bonded to twelve equivalent Pa atoms to form SiPa12 cuboctahedra that share corners with twelve equivalent SiPa12 cuboctahedra, edges with twenty-four equivalent PaPa8Si4 cuboctahedra, faces with six equivalent SiPa12 cuboctahedra, and faces with twelve equivalent PaPa8Si4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Sb by Materials Project

Pa3Sb is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Sb atoms to form distorted PaPa8Sb4 cuboctahedra that share corners with twelve equivalent PaPa8Sb4 cuboctahedra, edges with eight equivalent SbPa12 cuboctahedra, edges with sixteen equivalent PaPa8Sb4 cuboctahedra, faces with four equivalent SbPa12 cuboctahedra, and faces with fourteen equivalent PaPa8Sb4 cuboctahedra. All Pa–Pa bond lengths are 3.25 Å. All Pa–Sb bond lengths are 3.25 Å. Sb is bonded to twelve equivalent Pa atoms to form SbPa12 cuboctahedra that share corners with twelve equivalent SbPa12 cuboctahedra, edges with twenty-four equivalent PaPa8Sb4 cuboctahedra, faces with six equivalent SbPa12 cuboctahedra, and faces with twelve equivalent PaPa8Sb4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Te by Materials Project

Pa3Te is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Te atoms to form distorted PaPa8Te4 cuboctahedra that share corners with twelve equivalent PaPa8Te4 cuboctahedra, edges with eight equivalent TePa12 cuboctahedra, edges with sixteen equivalent PaPa8Te4 cuboctahedra, faces with four equivalent TePa12 cuboctahedra, and faces with fourteen equivalent PaPa8Te4 cuboctahedra. All Pa–Pa bond lengths are 3.24 Å. All Pa–Te bond lengths are 3.24 Å. Te is bonded to twelve equivalent Pa atoms to form TePa12 cuboctahedra that share corners with twelve equivalent TePa12 cuboctahedra, edges with twenty-four equivalent PaPa8Te4 cuboctahedra, faces with six equivalent TePa12 cuboctahedra, and faces with twelve equivalent PaPa8Te4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Ge by Materials Project

Pa3Ge is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Ge atoms to form distorted PaPa8Ge4 cuboctahedra that share corners with twelve equivalent PaPa8Ge4 cuboctahedra, edges with eight equivalent GePa12 cuboctahedra, edges with sixteen equivalent PaPa8Ge4 cuboctahedra, faces with four equivalent GePa12 cuboctahedra, and faces with fourteen equivalent PaPa8Ge4 cuboctahedra. All Pa–Pa bond lengths are 3.17 Å. All Pa–Ge bond lengths are 3.17 Å. Ge is bonded to twelve equivalent Pa atoms to form GePa12 cuboctahedra that share corners with twelve equivalent GePa12 cuboctahedra, edges with twenty-four equivalent PaPa8Ge4 cuboctahedra, faces with six equivalent GePa12 cuboctahedra, and faces with twelve equivalent PaPa8Ge4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pa3Re by Materials Project

Pa3Re is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Re atoms to form distorted PaPa8Re4 cuboctahedra that share corners with four equivalent RePa12 cuboctahedra, corners with fourteen equivalent PaPa8Re4 cuboctahedra, edges with six equivalent RePa12 cuboctahedra, edges with twelve equivalent PaPa8Re4 cuboctahedra, faces with four equivalent RePa12 cuboctahedra, and faces with sixteen equivalent PaPa8Re4 cuboctahedra. There are a spread of Pa–Pa bond distances ranging from 2.92–3.30 Å. There are two shorter (3.10 Å) and two longer (3.18 Å) Pa–Re bond lengths. Re is bonded to twelve equivalent Pa atoms to form RePa12 cuboctahedra that share corners with six equivalent RePa12 cuboctahedra, corners with twelve equivalent PaPa8Re4 cuboctahedra, edges with eighteen equivalent PaPa8Re4 cuboctahedra, faces with eight equivalent RePa12 cuboctahedra, and faces with twelve equivalent PaPa8Re4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdPa3 by Materials Project

Pa3Nd is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Nd atoms to form PaNd4Pa8 cuboctahedra that share corners with twelve equivalent PaNd4Pa8 cuboctahedra, edges with eight equivalent NdPa12 cuboctahedra, edges with sixteen equivalent PaNd4Pa8 cuboctahedra, faces with four equivalent NdPa12 cuboctahedra, and faces with fourteen equivalent PaNd4Pa8 cuboctahedra. All Pa–Pa bond lengths are 3.36 Å. All Pa–Nd bond lengths are 3.36 Å. Nd is bonded to twelve equivalent Pa atoms to form NdPa12 cuboctahedra that share corners with twelve equivalent NdPa12 cuboctahedra, edges with twenty-four equivalent PaNd4Pa8 cuboctahedra, faces with six equivalent NdPa12 cuboctahedra, and faces with twelve equivalent PaNd4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpPa3 by Materials Project

NpPa3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Np is bonded to twelve equivalent Pa atoms to form NpPa12 cuboctahedra that share corners with six equivalent NpPa12 cuboctahedra, corners with twelve equivalent PaNp4Pa8 cuboctahedra, edges with eighteen equivalent PaNp4Pa8 cuboctahedra, faces with eight equivalent NpPa12 cuboctahedra, and faces with twelve equivalent PaNp4Pa8 cuboctahedra. There are six shorter (3.09 Å) and six longer (3.32 Å) Np–Pa bond lengths. Pa is bonded to four equivalent Np and eight equivalent Pa atoms to form distorted PaNp4Pa8 cuboctahedra that share corners with four equivalent NpPa12 cuboctahedra, corners with fourteen equivalent PaNp4Pa8 cuboctahedra, edges with six equivalent NpPa12 cuboctahedra, edges with twelve equivalent PaNp4Pa8 cuboctahedra, faces with four equivalent NpPa12 cuboctahedra, and faces with sixteen equivalent PaNp4Pa8 cuboctahedra. There are a spread of Pa–Pa bond distances ranging from 3.07–3.33 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SmPa3 by Materials Project

Pa3Sm is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Sm atoms to form PaSm4Pa8 cuboctahedra that share corners with twelve equivalent PaSm4Pa8 cuboctahedra, edges with eight equivalent SmPa12 cuboctahedra, edges with sixteen equivalent PaSm4Pa8 cuboctahedra, faces with four equivalent SmPa12 cuboctahedra, and faces with fourteen equivalent PaSm4Pa8 cuboctahedra. All Pa–Pa bond lengths are 3.34 Å. All Pa–Sm bond lengths are 3.34 Å. Sm is bonded to twelve equivalent Pa atoms to form SmPa12 cuboctahedra that share corners with twelve equivalent SmPa12 cuboctahedra, edges with twenty-four equivalent PaSm4Pa8 cuboctahedra, faces with six equivalent SmPa12 cuboctahedra, and faces with twelve equivalent PaSm4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmPa3 by Materials Project

Pa3Tm is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pa is bonded to eight equivalent Pa and four equivalent Tm atoms to form PaTm4Pa8 cuboctahedra that share corners with twelve equivalent PaTm4Pa8 cuboctahedra, edges with eight equivalent TmPa12 cuboctahedra, edges with sixteen equivalent PaTm4Pa8 cuboctahedra, faces with four equivalent TmPa12 cuboctahedra, and faces with fourteen equivalent PaTm4Pa8 cuboctahedra. All Pa–Pa bond lengths are 3.33 Å. All Pa–Tm bond lengths are 3.33 Å. Tm is bonded to twelve equivalent Pa atoms to form TmPa12 cuboctahedra that share corners with twelve equivalent TmPa12 cuboctahedra, edges with twenty-four equivalent PaTm4Pa8 cuboctahedra, faces with six equivalent TmPa12 cuboctahedra, and faces with twelve equivalent PaTm4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗