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At least 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Activation of polycystin-1 signaling by binding of stalk-derived peptide agonists

Polycystin-1 (PC1) is the protein product of thePKD1gene whose mutation causes autosomal dominant Polycystic Kidney Disease (ADPKD). PC1 is an atypical G protein-coupled receptor (GPCR) with an autocatalytic GAIN domain that cleaves PC1 into extracellular N-terminal and membrane-embedded C-terminal (CTF) fragments. Recently, activation of PC1 CTF signaling was shown to be regulated by a stalk tethered agonist (TA), resembling the mechanism observed for adhesion GPCRs. Here, synthetic peptides of the first 9- (p9), 17- (p17), and 21-residues (p21) of the PC1 stalk TA were shown to re-activate signaling by a stalkless CTF mutant in human cell culture assays. Novel Peptide Gaussian accelerated molecular dynamics (Pep-GaMD) simulations elucidated binding conformations of p9, p17, and p21 and revealed multiple specific binding regions to the stalkless CTF. Peptide agonists binding to the TOP domain of PC1 induced close TOP-putative pore loop interactions, a characteristic feature of stalk TA-mediated PC1 CTF activation. Additional sequence coevolution analyses showed the peptide binding regions were consistent with covarying residue pairs identified between the TOP domain and the stalk TA. These insights into the structural dynamic mechanism of PC1 activation by TA peptide agonists provide an in-depth understanding that will facilitate the development of therapeutics targeting PC1 for ADPKD treatment.

Life Sciences & Biomedicine - Other Topics↗
NASA NTRS1975

Preparation of tantalum-based alloys by a unique CVD process

The paper describes a sequential pulsing technique for deposition of refractory alloys and evaluates the technique for the deposition of the tantalum-base alloys Ta-10W (Ta-10 st% W) and T-111 (Ta-8 wt% W-2 wt% Hf). The deposition cycle for Ta-10W was chosen as alternate injections of TaCl5 plus hydrogen and WCl6 plus hydrogen. The cycle for T-111 was chosen as injections of TaCl5 plus hydrogen interspersed with injections of WCl6 plus hydrogen. A temperature range of 900-1300 C was chosen for both alloys. The ability of the pulse process to blanket a uniformly heated section of substrate with a mixture of gases, whose composition varies not with position on the substrate but instead with time of residence in the reactor, allows metal of uniform thickness to be deposited. It is shown that Ta and W can be deposited at high temperature with the formation of a dense columnar grain structure, so that the feasibility of preparing uniformly thick deposits of these elements by a 'pulsing' modification of CVD is demonstrated. A similar attempt to deposit T-111 was unsuccessful due to the difficulty in reducing HfCl4.

Bryant, W. A.↗
NASA NTRS1982

Structure-property effects of tantalum additions to nickel-base superalloys

The characterization of the effect of Ta on the structure of Ni base superalloys, the determination of the effects of Ta (structure) variations on the mechanical, thermal, and oxidation behavior, and the identification of alloying elements which have potential as substitutes for Ta are investigated. Mar M247 type alloys are emphasized; nominal and analyzed compositions of ten alloys under study are given. X-ray and composition analysis are being used to determine the partitioning of alloying elements between gamma, gamma primes, and MC (cubic) as a function of Ta content. The diffusional interactions of the Mar M247-type alloys with as cast beta + gamma alloys are studied to determine the effects of Ta on alloy/coating degradation.

Heckel, R. W.↗
NASA NTRS1986

The effects of tantalum on the microstructure of two polycrystalline nickel-base superalloys - B-1900 + Hf and MAR-M247

The effect of changing the content of Ta on the gamma/gamma-prime carbide microstructure was investigated in two crystalline nickel-base superalloys: conventionally cast B-1900 + Hf, and both conventionally cast and directionally solidified MAR-M247. The changes occurring in the microstructure effects were similar in both alloys. The gamma-prime and carbide volume fractions increased linearly with Ta additions, while the gamma-prime phase compositions did not change. Bulk Ta additions increased the levels of Cr and Co (in addition to that of Ta) of the gamma phase, a result of the approximately constant partitioning ratios for these two elements. The addition of Ta led to a partial replacement of Hf in the MC carbides. In addition, Cr-rich M(23)C(6) carbides formed as a result of MC carbide decomposition during heat treatment.

Heckel, R. W.↗
NASA NTRS1992

Effects of microgravity and tail suspension on enzymes of individual soleus and tibialis anterior fibers

Selected enzymes of energy metabolism were measured in random individual fibers of soleus and tibialis anterior (TA) muscles from rats exposed for 2 wk to spaceflight (F) aboard Cosmos 2044 or tail suspension (T) and from synchronous controls. Average size of soleus fibers (dry weight per unit length) was reduced 37 percent in F and T fibers; there was little change in Ta fibers. Enzyme changes were more pronounced in soleus than in TA fibers. Three enzymes characteristic of fast-twitch muscles, pyruvate kinase, glycerol-3-phosphate dehydrogenase, and 1-phosphofructokinase, were elevated in F and T soleus fibers, but changes in phosphofructokinase were not statistically significant. In TA fibers analyzed for hexokinase, malate dehydrogenase, phosphohexoisomerase, and pyruvate kinase, only hexokinase and malate dehydrogenase showed significant changes. Hexokinase incresed 83 percent in one of two T muscles. Enzyme data for TA fibers typed by myosin adenosinetriphosphatase were more informative: phosphofructokinase, phosphorylase, and glycerol-3-phosphate dehydrogenase were increased in type IIn fibers of either F or T muscles or both. Malate dehydrogenase was not changed in fibers of any type in either F or T muscle.

Chi, Maggie M.-Y.↗
NASA NTRS1994

Hot gas ingestion effects on fuel control surge recovery and AH-1 rotor drive train torque spikes

This report summarizes the work accomplished through computer simulation to understand the impact of the hydromechanical turbine assembly (TA) fuel control on rocket gas ingestion induced engine surges on the AH-1 (Cobra) helicopter. These surges excite the lightly damped torsional modes of the Cobra rotor drive train and can cause overtorqueing of the tail rotor shaft. The simulation studies show that the hydromechanical TA control has a negligible effect on drive train resonances because its response is sufficiently attenuated at the resonant frequencies. However, a digital electronic control working through the TA control's separate, emergency fuel metering system has been identified as a solution to the overtorqueing problem. State-of-the-art software within the electronic control can provide active damping of the rotor drive train to eliminate excessive torque spikes due to any disturbances including engine surges and aggressive helicopter maneuvers. Modifications to the existing TA hydromechanical control are relatively minor, and existing engine sensors can be utilized by the electronic control. Therefore, it is concluded that the combination of full authority digital electronic control (FADEC) with hydromechanical backup using the existing TA control enhances flight safety, improves helicopter performance, reduces pilot workload, and provides a substantial payback for very little investment.

Tokarski, Frank↗
NASA NTRS2000

Multisorbent tubes for collecting volatile organic compounds in spacecraft air

The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.

NASA Center JSC↗
NASA NTRS1999

Effects of spaceflight on rhesus quadrupedal locomotion after return to 1G

Effects of spaceflight on Rhesus quadrupedal locomotion after return to 1G. Locomotor performance, activation patterns of the soleus (Sol), medial gastrocnemius (MG), vastus lateralis (VL), and tibialis anterior (TA) and MG tendon force during quadrupedal stepping were studied in adult Rhesus before and after 14 days of either spaceflight (n = 2) or flight simulation at 1G (n = 3). Flight simulation involved duplication of the spaceflight conditions and experimental protocol in a 1G environment. Postflight, but not postsimulation, electromyographic (EMG) recordings revealed clonus-like activity in all muscles. Compared with preflight, the cycle period and burst durations of the primary extensors (Sol, MG, and VL) tended to decrease postflight. These decreases were associated with shorter steps. The flexor (TA) EMG burst duration postflight was similar to preflight, whereas the burst amplitude was elevated. Consequently, the Sol:TA and MG:TA EMG amplitude ratios were lower following flight, reflecting a "flexor bias." Together, these alterations in mean EMG amplitudes reflect differential adaptations in motor-unit recruitment patterns of flexors and extensors as well as fast and slow motor pools. Shorter cycle period and burst durations persisted throughout the 20-day postflight testing period, whereas mean EMG returned to preflight levels by 17 days postflight. Compared with presimulation, the simulation group showed slight increases in the cycle period and burst durations of all muscles. Mean EMG amplitude decreased in the Sol, increased in the MG and VL, and was unchanged in the TA. Thus adaptations observed postsimulation were different from those observed postflight, indicating that there was a response unique to the microgravity environment, i.e., the modulations in the nervous system controlling locomotion cannot merely be attributed to restriction of movement but appear to be the result of changes in the interpretation of load-related proprioceptive feedback to the nervous system. Peak MG tendon force amplitudes were approximately two times greater post- compared with preflight or presimulation. Adaptations in tendon force and EMG amplitude ratios indicate that the nervous system undergoes a reorganization of the recruitment patterns biased toward an increased recruitment of fast versus slow motor units and flexor versus extensor muscles. Combined, these data indicate that some details of the control of motor pools during locomotion are dependent on the persistence of Earth's gravitational environment.

Bion 11 Project↗
NASA NTRS2012

The Aquarius Salinity Retrieval Algorithm: Early Results

The Aquarius L-band radiometer/scatterometer system is designed to provide monthly salinity maps at 150 km spatial scale to a 0.2 psu accuracy. The sensor was launched on June 10, 2011, aboard the Argentine CONAE SAC-D spacecraft. The L-band radiometers and the scatterometer have been taking science data observations since August 25, 2011. The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to O2, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind. This is based on the radar backscatter measurements by the scatterometer. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water and an auxiliary field for the sea surface temperature. In the current processing (as of writing this abstract) only v-pol TB are used for this last process and NCEP winds are used for the roughness correction. Before the salinity algorithm can be operationally implemented and its accuracy assessed by comparing versus in situ measurements, an extensive calibration and validation (cal/val) activity needs to be completed. This is necessary in order to tune the inputs to the algorithm and remove biases that arise due to the instrument calibration, foremost the values of the noise diode injection temperatures and the losses that occur in the feedhorns. This is the subject of the second part of our presentation. The basic tool is to analyze the observed difference between the Aquarius measured TA and an expected TA that is computed from a reference salinity field. It is also necessary to derive a relation between the scatterometer backscatter measurements and the radiometer emissivity that is induced by surface winds. In order to do this we collocate Aquarius radiometer and scatterometer measurements with wind speed retrievals from the WindSat and SSMIS F17 microwave radiometers. Both of these satellites fly in orbits that have the same equatorial ascending crossing time (6 pm) as the Aquarius/SAC-D observatory. Rain retrievals from WindSat and SSMIS F 17 can be used to remove Aquarius observations that are rain contaminated. A byproduct of this analysis is a prediction for the wind-induced sea surface emissivity at L-band.

Meissner, Thomas↗
DOE OSTI2020

Materials Data on TaGa3 by Materials Project

TaGa3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ta is bonded to twelve Ga atoms to form TaGa12 cuboctahedra that share corners with four equivalent TaGa12 cuboctahedra, edges with eight equivalent TaGa12 cuboctahedra, edges with sixteen equivalent GaTa4Ga8 cuboctahedra, faces with four equivalent TaGa12 cuboctahedra, and faces with eight equivalent GaTa4Ga8 cuboctahedra. There are four shorter (2.71 Å) and eight longer (2.91 Å) Ta–Ga bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a distorted square co-planar geometry to four equivalent Ta and eight equivalent Ga atoms. All Ga–Ga bond lengths are 2.91 Å. In the second Ga site, Ga is bonded to four equivalent Ta and eight Ga atoms to form GaTa4Ga8 cuboctahedra that share corners with twelve equivalent GaTa4Ga8 cuboctahedra, edges with eight equivalent TaGa12 cuboctahedra, edges with eight equivalent GaTa4Ga8 cuboctahedra, faces with four equivalent TaGa12 cuboctahedra, and faces with ten equivalent GaTa4Ga8 cuboctahedra. All Ga–Ga bond lengths are 2.71 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaTe2 by Materials Project

TaTe2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one TaTe2 sheet oriented in the (2, 0, -1) direction. there are four inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six Te2- atoms to form distorted edge-sharing TaTe6 octahedra. There are a spread of Ta–Te bond distances ranging from 2.70–2.94 Å. In the second Ta4+ site, Ta4+ is bonded to six Te2- atoms to form distorted edge-sharing TaTe6 octahedra. There are a spread of Ta–Te bond distances ranging from 2.65–2.93 Å. In the third Ta4+ site, Ta4+ is bonded to six Te2- atoms to form distorted edge-sharing TaTe6 octahedra. There are a spread of Ta–Te bond distances ranging from 2.77–2.94 Å. In the fourth Ta4+ site, Ta4+ is bonded to six Te2- atoms to form distorted edge-sharing TaTe6 octahedra. There are four shorter (2.89 Å) and two longer (2.91 Å) Ta–Te bond lengths. There are six inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the second Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ta4+ atoms. In the third Te2- site, Te2- is bonded in a distorted trigonal non-coplanar geometry to three Ta4+ atoms. In the fourth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the fifth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the sixth Te2- site, Te2- is bonded in a 3-coordinate geometry to three Ta4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2Ta15O32 by Materials Project

Ba2Ta15O32 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with six TaO6 octahedra, edges with three equivalent BaO12 cuboctahedra, edges with three equivalent TaO6 octahedra, edges with three equivalent TaO5 square pyramids, and faces with three equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 44–55°. There are a spread of Ba–O bond distances ranging from 2.94–3.19 Å. There are four inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to five O2- atoms to form TaO5 square pyramids that share corners with four TaO6 octahedra, corners with four equivalent TaO5 square pyramids, an edgeedge with one BaO12 cuboctahedra, and an edgeedge with one TaO6 octahedra. The corner-sharing octahedra tilt angles range from 7–54°. There are a spread of Ta–O bond distances ranging from 2.06–2.22 Å. In the second Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent TaO5 square pyramids, and edges with three equivalent TaO5 square pyramids. The corner-sharing octahedral tilt angles are 42°. There are three shorter (1.95 Å) and three longer (2.08 Å) Ta–O bond lengths. In the third Ta4+ site, Ta4+ is bonded to six O2- atoms to form TaO6 octahedra that share a cornercorner with one BaO12 cuboctahedra, corners with two TaO6 octahedra, corners with three equivalent TaO5 square pyramids, an edgeedge with one BaO12 cuboctahedra, edges with two equivalent TaO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–42°. There are a spread of Ta–O bond distances ranging from 1.91–2.11 Å. In the fourth Ta4+ site, Ta4+ is bonded to six equivalent O2- atoms to form TaO6 octahedra that share corners with six equivalent BaO12 cuboctahedra and corners with six equivalent TaO6 octahedra. The corner-sharing octahedral tilt angles are 38°. All Ta–O bond lengths are 2.00 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Ta4+ atoms. In the second O2- site, O2- is bonded in a T-shaped geometry to three Ta4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ta4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+ and two Ta4+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two equivalent Ta4+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta4SiTe4 by Materials Project

Ta4SiTe4 crystallizes in the orthorhombic Pbam space group. The structure is one-dimensional and consists of two Ta4SiTe4 ribbons oriented in the (1, 0, 0) direction. there are two inequivalent Ta3+ sites. In the first Ta3+ site, Ta3+ is bonded to two equivalent Si4- and four Te2- atoms to form a mixture of distorted edge, face, and corner-sharing TaSi2Te4 octahedra. The corner-sharing octahedra tilt angles range from 40–69°. Both Ta–Si bond lengths are 2.60 Å. There are two shorter (2.86 Å) and two longer (2.94 Å) Ta–Te bond lengths. In the second Ta3+ site, Ta3+ is bonded to two equivalent Si4- and four Te2- atoms to form a mixture of distorted edge, face, and corner-sharing TaSi2Te4 octahedra. The corner-sharing octahedra tilt angles range from 40–70°. Both Ta–Si bond lengths are 2.61 Å. There are two shorter (2.86 Å) and two longer (2.94 Å) Ta–Te bond lengths. Si4- is bonded in a 10-coordinate geometry to eight Ta3+ and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.42 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 4-coordinate geometry to four Ta3+ atoms. In the second Te2- site, Te2- is bonded in a 4-coordinate geometry to four Ta3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba3(TaS4)2 by Materials Project

Ba3Ta2S8 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are five inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a distorted body-centered cubic geometry to eight S2- atoms. There are four shorter (3.28 Å) and four longer (3.29 Å) Ba–S bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.52 Å. In the third Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.53 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.53 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.65 Å. There are four inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six S2- atoms to form face-sharing TaS6 octahedra. There are two shorter (2.42 Å) and four longer (2.47 Å) Ta–S bond lengths. In the second Ta5+ site, Ta5+ is bonded to six S2- atoms to form face-sharing TaS6 octahedra. There are two shorter (2.42 Å) and four longer (2.47 Å) Ta–S bond lengths. In the third Ta5+ site, Ta5+ is bonded to six S2- atoms to form face-sharing TaS6 octahedra. There are a spread of Ta–S bond distances ranging from 2.31–2.66 Å. In the fourth Ta5+ site, Ta5+ is bonded to six S2- atoms to form distorted face-sharing TaS6 octahedra. There are a spread of Ta–S bond distances ranging from 2.31–2.66 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to four Ba2+ and one Ta5+ atom. In the second S2- site, S2- is bonded in a 1-coordinate geometry to four Ba2+ and one Ta5+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to three Ba2+ and two Ta5+ atoms. In the fourth S2- site, S2- is bonded in a 1-coordinate geometry to four Ba2+ and one Ta5+ atom. In the fifth S2- site, S2- is bonded in a distorted single-bond geometry to four Ba2+ and one Ta5+ atom. In the sixth S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+ and two Ta5+ atoms. In the seventh S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+ and two Ta5+ atoms. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to three Ba2+ and two Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La3(TaN3)2 by Materials Project

La3(TaN3)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 1-coordinate geometry to nine N3- atoms. There are a spread of La–N bond distances ranging from 2.45–2.91 Å. In the second La3+ site, La3+ is bonded in a body-centered cubic geometry to eight equivalent N3- atoms. All La–N bond lengths are 2.68 Å. Ta+4.50+ is bonded to five N3- atoms to form corner-sharing TaN5 square pyramids. There are one shorter (1.96 Å) and four longer (2.07 Å) Ta–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four La3+ and two equivalent Ta+4.50+ atoms to form a mixture of distorted face, edge, and corner-sharing NLa4Ta2 octahedra. The corner-sharing octahedra tilt angles range from 0–65°. In the second N3- site, N3- is bonded in a 6-coordinate geometry to five equivalent La3+ and one Ta+4.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaPd3 by Materials Project

Pd3Ta is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ta is bonded to twelve Pd atoms to form TaPd12 cuboctahedra that share corners with four equivalent TaPd12 cuboctahedra, edges with eight equivalent TaPd12 cuboctahedra, edges with sixteen equivalent PdTa4Pd8 cuboctahedra, faces with four equivalent TaPd12 cuboctahedra, and faces with eight equivalent PdTa4Pd8 cuboctahedra. There are four shorter (2.78 Å) and eight longer (2.82 Å) Ta–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 Ta and eight equivalent Pd atoms. All Pd–Pd bond lengths are 2.82 Å. In the second Pd site, Pd is bonded to four equivalent Ta and eight Pd atoms to form distorted PdTa4Pd8 cuboctahedra that share corners with twelve equivalent PdTa4Pd8 cuboctahedra, edges with eight equivalent TaPd12 cuboctahedra, edges with eight equivalent PdTa4Pd8 cuboctahedra, faces with four equivalent TaPd12 cuboctahedra, and faces with ten equivalent PdTa4Pd8 cuboctahedra. All Pd–Pd bond lengths are 2.78 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaPt3 by Materials Project

TaPt3 is beta Cu3Ti structured and crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ta is bonded to twelve Pt atoms to form TaPt12 cuboctahedra that share corners with two equivalent TaPt12 cuboctahedra, corners with eight equivalent PtTa4Pt8 cuboctahedra, edges with six equivalent TaPt12 cuboctahedra, edges with twelve equivalent PtTa4Pt8 cuboctahedra, faces with six equivalent TaPt12 cuboctahedra, and faces with eight equivalent PtTa4Pt8 cuboctahedra. There are a spread of Ta–Pt bond distances ranging from 2.79–2.86 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded to four equivalent Ta and eight Pt atoms to form distorted PtTa4Pt8 cuboctahedra that share corners with four equivalent TaPt12 cuboctahedra, corners with ten equivalent PtTa4Pt8 cuboctahedra, edges with six equivalent TaPt12 cuboctahedra, edges with six equivalent PtTa4Pt8 cuboctahedra, faces with four equivalent TaPt12 cuboctahedra, and faces with twelve equivalent PtTa4Pt8 cuboctahedra. There are a spread of Pt–Pt bond distances ranging from 2.80–2.87 Å. In the second Pt site, Pt is bonded in a distorted see-saw-like geometry to four equivalent Ta and eight equivalent Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ta3SBr7 by Materials Project

Ta3SBr7 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of one Ta3SBr7 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Ta3+ sites. In the first Ta3+ site, Ta3+ is bonded to one S2- and five Br1- atoms to form distorted edge-sharing TaSBr5 octahedra. The Ta–S bond length is 2.41 Å. There are a spread of Ta–Br bond distances ranging from 2.56–2.84 Å. In the second Ta3+ site, Ta3+ is bonded to one S2- and five Br1- atoms to form distorted edge-sharing TaSBr5 octahedra. The Ta–S bond length is 2.41 Å. There are a spread of Ta–Br bond distances ranging from 2.56–2.84 Å. S2- is bonded in a 3-coordinate geometry to three Ta3+ atoms. There are five inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 2-coordinate geometry to two Ta3+ atoms. In the second Br1- site, Br1- is bonded in a 3-coordinate geometry to three Ta3+ atoms. In the third Br1- site, Br1- is bonded in a water-like geometry to two equivalent Ta3+ atoms. In the fourth Br1- site, Br1- is bonded in a 2-coordinate geometry to two equivalent Ta3+ atoms. In the fifth Br1- site, Br1- is bonded in a water-like geometry to two Ta3+ atoms.

36 MATERIALS SCIENCE↗