Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Pt(NO)6”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Suppression of the valence transition in solution-grown single crystals of Eu 2 Pt 6 Al 15

Here, the study of Eu intermetallic compounds has allowed the exploration of valence fluctuations and transitions in 4⁢𝑓 electron systems. Recently, a Eu 2 ⁢Pt 6 ⁢Al 15 phase synthesized by arc-melting followed by a thermal treatment was reported M. Radzieowski et al. [J. Am. Chem. Soc. 140, 8950 (2018)], which undergoes a transition upon cooling below 45 K that was interpreted as a valence transition from Eu 2+ to Eu 3+ . In this paper, we present the discovery of another polymorph of Eu 2 ⁢Pt 6 ⁢Al 15 obtained by high temperature solution growth, which presents different physical properties than the arc-melted polycrystalline sample. Despite the similarities in crystal structure and chemical composition, the Eu valence transition is almost fully suppressed in the solution-grown crystals, allowing the moments associated with the Eu 2+ state to order antiferromagnetically at around 14 K. A detailed analysis of the crystal structure using single crystal x-ray diffraction reveals that, although the solution grown crystals are built from the same constituent layers as the arc-melted samples, these layers present a different stacking. The effect of different thermal treatments is also studied. Different anneal procedures did not result in significant changes in the intrinsic properties, and only by arc-melting and quenching the crystals we were able to convert them into the previously reported polymorph.

Schmidt, Juan [Ames Laboratory, and Iowa State Uni↗
DOE OSTI2026

Growth, discovery and characterization of single crystalline Eu 0.8 Pt 6 Al 16.4

Here, we report the discovery of a ternary compound, Eu 0.8 Pt 6 Al1 6.4 . We determine its chemical and structural characteristics based on energy-dispersive X-ray spectroscopy as well as both powder and single-crystal X-ray diffraction, demonstrating that it crystallizes in a hexagonal structure type EuPt 6 Al 17 with no reported structural analog. The temperature- and field-dependent magnetization, and temperature-dependent resistance measurements, reveal that the Eu 2+ magnetic moments order antiferromagnetically below 2.8 K.

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

Structures and Magnetic Properties of K 2 Pd 4 U 6 S 17 , K 2 Pt 4 U 6 S 17 , Rb 2 Pt 4 U 6 S 17 , and Cs 2 Pt 4 U 6 S 17 Synthesized Using the Boron–Chalcogen Mixture Method

A series of A 2 M 4 U 6 S 17 (A = Alkali metal, M = Pd or Pt) compounds, specifically K 2 Pd 4 U 6 S 17 , K 2 Pt 4 U 6 S 17 , Rb 2 Pt 4 U 6 S 17 , and Cs 2 Pt 4 U 6 S 17 , were synthesized using the combined Boron-Chalcogen Mixture (BCM) and molten flux crystal growth methods. The formation of the Rb- and Cs- containing analogues resulted from the in-situ alkali polysulfide flux formation formed from the alkali carbonates. The successful synthesis of single crystals of the title compounds allowed for their structural characterization by single crystal X-ray diffraction. The structure determination revealed disorder of the alkali cations in Rb 2 Pt 4 U 6 S 17 , and Cs 2 Pt 4 U 6 S 17 , while the potassium cations in K 2 Pd 4 U 6 S 17 and K 2 Pt 4 U 6 S 17 were fully ordered. Here, magnetic measurements were performed on samples of K 2 Pt 4 U 6 S 17 , Rb 2 Pt 4 U 6 S 17 , and Cs 2 Pt 4 U 6 S 17 that contained small amounts of paramagnetic β-US 2 and diamagnetic PtS. Antiferromagnetic order is observed at T N = 9.1 K for K 2 Pt 4 U 6 S 17 . No long-range magnetic order was observed for Rb 2 Pt 4 U 6 S 17 and Cs 2 Pt 4 U 6 S 17 . Uranium moments of 2.5, 2.6, and 2.6 μB were measured for K 2 Pt 4 U 6 S 17 , Rb 2 Pt 4 U 6 S 17 , and Cs 2 Pt 4 U 6 S 17 , respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Toward Quantum Chemical Free Energy Simulations of Platinum Nanoparticles on Titania Support

Platinum nanoparticles (Pt-NPs) supported on titania surfaces are costly but indispensable heterogeneous catalysts because of their highly effective and selective catalytic properties. Therefore, it is vital to understand their physicochemical processes during catalysis to optimize their use and to further develop better catalysts. However, simulating these dynamic processes is challenging due to the need for a reliable quantum chemical method to describe chemical bond breaking and bond formation during the processes but, at the same time, fast enough to sample a large number of configurations required to compute the corresponding free energy surfaces. Density functional theory (DFT) is often used to explore Pt-NPs; nonetheless, it is usually limited to some minimum-energy reaction pathways on static potential energy surfaces because of its high computational cost. In this work, we report a combination of the density functional tight binding (DFTB) method as a fast but reliable approximation to DFT, the steered molecular dynamics (SMD) technique, and the Jarzynski equality to construct free energy surfaces of the temperature-dependent diffusion and growth of platinum particles on a titania surface. In particular, we present the parametrization for Pt-X (X = Pt, Ti, or O) interactions in the framework of the second-order DFTB method, using a previous parametrization for titania as a basis. The optimized parameter set was used to simulate the surface diffusion of a single platinum atom (Pt 1 ) and the growth of Pt 6 from Pt 5 and Pt 1 on the rutile (110) surface at three different temperatures (T = 400, 600, 800 K). The free energy profile was constructed by using over a hundred SMD trajectories for each process. We found that increasing the temperature has a minimal effect on the formation free energy; nevertheless, it significantly reduces the free energy barrier of Pt atom migration on the TiO 2 surface and the transition state (TS) of its deposition. In a concluding remark, the methodology opens the pathway to quantum chemical free energy simulations of Pt-NPs’ temperature-dependent growth and other transformation processes on the titania support.

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

Materials Data on Pt(NO)6 by Materials Project

PtN2N2(NO3)2 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of sixteen ammonia molecules, eight cis-platinum-(nh3)2 molecules, and sixteen nitric acid molecules.

36 MATERIALS SCIENCE↗
NASA NTRS2010

Highly Siderophile Elements as Tracers for the Subcontinental Mantle Evolution Beneath the Southwestern USA: The San Carlos and Kilbourne Hole Peridotite Xenoliths Revisited

Peridotite xenoliths from San Carlos, Arizona, and Kilbourne Hole, New Mexico, have been studied since the 1970 s to give insights into melting and metasomatism in the subcontinental mantle beneath the southwestern USA. More recently, the highly siderophile elements (HSE; Os, Ir, Ru, Rh, Pt, Pd, and Re) and the included Re-Os isotope system have been established as powerful tools for the study of mantle processes because of their range in compatibility during mantle melting and their siderophile and chalcophile geochemical behavior. Model aluminachron Re-Os ages for San Carlos and Kilbourne Hole, as well as for the nearby Dish Hill and Vulcan's Throne sites, give consistent depletion ages of around 2.2 Ga. This age can be interpreted as a single large scale mantle melting event linked to crustal formation and continental growth under the southwestern USA. Highly siderophile elements, however, may be added to depleted peridotites via melt-rock interaction, especially the more incompatible and hence mobile Pt, Pd, and Re. This may result in overprinting of the signature of melt extraction, thus abating the usefulness of Re-Os mantle extraction model ages. A comprehensive characterization of the suite of mantle xenoliths from the SW USA in terms of HSE concentrations is thus necessary to re-assess the Re-Os system for dating purposes. San Carlos peridotites are depleted to moderately fertile, as indicated by their bulk Al2O3 contents between 0.66 wt% and 3.13 wt%. Bulk Os-187/Os-188 in San Carlos peridotites range from 0.1206 to 0.1357. In contrast, Kilbourne Hole peridotites tend to be more fertile with Al2O3 between 2.11 and 3.78 wt%, excluding one extremely depleted sample with 0.30 wt% Al2O3, and have Os-187/Os-188 between 0.1156 and 0.1272, typical for mantle peridotites. No large fractionation between the more compatible HSE Os, Ir, and Ru are observed. The more incompatible HSE Re, Pd, and to a minor extent, Pt, however, are depleted in a number of samples by factors of up to 4 for Pt, 6 for Pd, and 20 for Re, compared to primitive mantle estimates. This is in agreement with previous studies from the same locales, which demonstrated the presence of different populations of mantle xenoliths having undergone various degrees of melt extraction. The depletion of the more incompatible elements (Re, Pd, and Pt) also suggests that the HSE budgets of the SW USA peridotites were primarily established by extraction of basaltic melt, and reflect only minor influence from later episodes of metasomatism. Model Re-Os ages obtained from San Carlos and Kilbourne Hole xenoliths may thus reflect ages of crustal formation and mantle depletion in the SW USA region.

vanAcken, D.↗
DOE OSTI2025

The [M 6 (S 2 C 2 Ph 2 ) 6 ] (M = Ni, Pd, Pt) Series: Multielectron Reservoirs That Sustain Ligand-Based Oxidations and Metal-Based Reductions

A complete [M 6 (S 2 C 2 R 2 ) 6 ] series (M = Ni (1), Pd (2), Pt (3); R = Ph), the rarest variety among homoleptic dithiolene transition-metal compounds, has been prepared by reaction between [M(S 2 C 2 Ph 2 ) 2 ] and a M 0 source. The platinum member of this set is the first of its type. Diffraction-quality crystals, grown with high reproducibility by evaporation from PhNO 2 solutions, reveal fully reduced [Ph 2 C 2 S 2 ] 2– dianions and an octahedral M 6 core that is reduced to C 2 symmetry by the fusion of a mononuclear D 2h [M(S 2 C 2 Ph 2 ) 2 ] fragment upon a C 4 -symmetric base. The [Ni 6 (S 2 C 2 Ph 2 ) 2 ] 1– monoanion, prepared by Cp* 2 Co reduction, shows only modest structural differences from its neutral counterpart. In CH 2 Cl 2 , 1 and 2 can undergo two reductions and an oxidation, while 3 sustains two reductions and two oxidations. In benzonitrile, 1 sustains three reversible oxidations at potentials that are shifted appreciably to less positive values. The cathodic processes are shown by density functional theory (DFT) calculations to involve an MO largely of metal–sulfur composition that has contributions throughout the C 4 -symmetric pentametallic base of the assembly, while the oxidations are largely ligand-based and confined to the monometallic [M(S 2 C 2 Ph 2 ) 2 ] cap. The absorption spectra are marked by multiple overlapping bands that produce a continuous, tapering absorption profile of unresolved shoulders and swells.

Ligands↗
DOE OSTI2021

Atomic Structure Evolution of Pt–Co Binary Catalysts: Single Metal Sites versus Intermetallic Nanocrystals

Due to their exceptional catalytic properties for the oxygen reduction reaction (ORR) and other crucial electrochemical reactions, PtCo intermetallic nanoparticle (NP) and single atomic (SA) Pt metal site catalysts have received considerable attention. However, their formation mechanisms at the atomic level during high-temperature annealing processes remain elusive. Furthermore, the thermally driven structure evolution of Pt–Co binary catalyst systems is investigated using advanced in situ electron microscopy, including PtCo intermetallic alloys and single Pt/Co metal sites. The pre-doping of CoN 4 sites in carbon supports and the initial Pt NP sizes play essential roles in forming either Pt 3 Co intermetallics or single Pt/Co metal sites. Importantly, the initial Pt NP loadings against the carbon support are critical to whether alloying to L1 2 -ordered Pt 3 Co NPs or atomizing to SA Pt sites at high temperatures. High Pt NP loadings (e.g., 20%) tend to lead to the formation of highly ordered Pt 3 Co intermetallic NPs with excellent activity and enhanced stability toward the ORR. In contrast, at a relatively low Pt loading (<6 wt%), the formation of single Pt sites in the form of PtC 3 N is thermodynamically favorable, in which a synergy between the PtC 3 N and the CoN 4 sites could enhance the catalytic activity for the ORR, but showing insufficient stability.

36 MATERIALS SCIENCE↗
NASA NTRS1976

Refinement of Promising Coating Compositions for Directionally Cast Eutectics

The successful application of high creep strength, directionally solidified gamma/gamma prime-delta (Ni-19.7Cb-6Cr-2.5Al) eutectic superalloy turbine blades requires the development of suitable coatings for airfoil, root and internal blade surfaces. In order to improve coatings for the gamma/gamma prime-delta alloy, the current investigation had the goals of (1) refining promising coating compositions for directionally solidified eutectics, (2) evaluating the effects of coating/ substrate interactions on the mechanical properties of the alloy, and (3) evaluating diffusion aluminide coatings for internal surfaces. Burner rig cyclic oxidation, furnace cyclic hot corrosion, ductility, and thermal fatigue tests indicated that NiCrAlY+Pt(63 to 127 micron Ni-18Cr-12Al-0.3Y + 6 micron Pt) and NiCrAlY(63 to 127 micron Ni-18Cr-12Al-0.3Y) coatings are capable of protecting high temperature gas path surfaces of eutectic alloy airfoils. Burner rig (Mach 0.37) testing indicated that the useful coating life of the 127 micron thick coatings exceeded 1000 hours at 1366 K (2000 deg F). Isothermal fatigue and furnance hot corrosion tests indicated that 63 micron NiCrAlY, NiCrAlY + Pt and platinum modified diffusion aluminide (Pt + Al) coating systems are capable of protecting the relatively cooler surfaces of the blade root. Finally, a gas phase coating process was evaluated for diffusion aluminizing internal surfaces and cooling holes of air-cooled gamma/gamma prime-delta turbine blades.

Strangman, T. E.↗
DOE OSTI2020

Materials Data on K2Ag4Pt3(NO2)12 by Materials Project

(KAg2(NO2)6)2(Pt)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of six platinum molecules and one KAg2(NO2)6 framework. In the KAg2(NO2)6 framework, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.26 Å. There are two inequivalent Ag2+ sites. In the first Ag2+ site, Ag2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.41–2.59 Å. In the second Ag2+ site, Ag2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.44–2.94 Å. There are six inequivalent N+1.67+ sites. In the first N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.25 Å) N–O bond length. In the second N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.26 Å) N–O bond length. In the third N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.26 Å) N–O bond length. In the fourth N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both N–O bond lengths are 1.25 Å. In the fifth N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.26 Å) N–O bond length. In the sixth N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both N–O bond lengths are 1.25 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ag2+ and one N+1.67+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag2+ and one N+1.67+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one N+1.67+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Ag2+, and one N+1.67+ atom. In the twelfth O2- site, O2- is bonded in a single-bond geometry to one N+1.67+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1990

Analysis of Pt/SnO(sub x) during catalysis of CO oxidation

Temperature-programmed reduction using 6kPaH2 suggests that a sample consisting of 3 percent Pt supported directly on SnO2 is, under conditions of catalysis of CO oxidation used here, best represented as 3 percent Pt/SnO sub x, since the support is likely to partially reduced, probably in the vicinity of the metal/oxide interface. Catalytic measurements at 421 to 424 K show that this 3 percent Pt/SnO sub x is significantly more active per unit area of Pt than 6 percent Pt/SiO2 in catalyzing the oxidation of CO. In situ micro-FTIR reveals that while the latter has predominantly linearly bound CO on the surface under reaction conditions, the Pt/SnO sub x also has a species absorbing at 2168 cm(exp -1) which may be CO upon Pt in a positive oxidation state or weakly chemisorbed CO on zero-valent Pt. This may be directly involved in the low temperature oxidation of CO on the Pt/SnO sub x, since being weakly held the activation energy for its surface diffusion to the metal/oxide interface will be low; such mobile species could allow the high rates of surface transport and an increase in the fraction of the surface over which the CO oxidation occurs. FTIR also reveals carbonate-type species on the P/SnO sub c surface.

Sermon, Paul A.↗
DOE OSTI2020

Materials Data on Pr12InPt7 by Materials Project

Pr12Pt7In crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are three inequivalent Pr sites. In the first Pr site, Pr is bonded in a 6-coordinate geometry to five Pt and one In atom. There are a spread of Pr–Pt bond distances ranging from 3.00–3.45 Å. The Pr–In bond length is 3.41 Å. In the second Pr site, Pr is bonded in a 2-coordinate geometry to five Pt atoms. There are a spread of Pr–Pt bond distances ranging from 2.87–3.72 Å. In the third Pr site, Pr is bonded in a 4-coordinate geometry to four Pt atoms. There are two shorter (2.95 Å) and two longer (3.14 Å) Pr–Pt bond lengths. There are three inequivalent Pt sites. In the first Pt site, Pt is bonded in a 10-coordinate geometry to eight Pr atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to nine Pr atoms. In the third Pt site, Pt is bonded in a 8-coordinate geometry to eight equivalent Pr atoms. In is bonded in a body-centered cubic geometry to eight equivalent Pr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd12InPt7 by Materials Project

Nd12Pt7In crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are three inequivalent Nd sites. In the first Nd site, Nd is bonded in a 6-coordinate geometry to five Pt and one In atom. There are a spread of Nd–Pt bond distances ranging from 2.97–3.41 Å. The Nd–In bond length is 3.38 Å. In the second Nd site, Nd is bonded in a 2-coordinate geometry to five Pt atoms. There are a spread of Nd–Pt bond distances ranging from 2.86–3.72 Å. In the third Nd site, Nd is bonded in a 4-coordinate geometry to four Pt atoms. There are two shorter (2.92 Å) and two longer (3.14 Å) Nd–Pt bond lengths. There are three inequivalent Pt sites. In the first Pt site, Pt is bonded in a 8-coordinate geometry to eight equivalent Nd atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to nine Nd atoms. In the third Pt site, Pt is bonded in a 10-coordinate geometry to eight Nd atoms. In is bonded in a body-centered cubic geometry to eight equivalent Nd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3Pt by Materials Project

Gd3Pt is Cementite structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Gd sites. In the first Gd site, Gd is bonded in a 2-coordinate geometry to three Pt atoms. There are a spread of Gd–Pt bond distances ranging from 2.91–3.40 Å. In the second Gd site, Gd is bonded in a 2-coordinate geometry to three Pt atoms. There are a spread of Gd–Pt bond distances ranging from 2.91–3.42 Å. In the third Gd site, Gd is bonded in a 2-coordinate geometry to three Pt atoms. There are a spread of Gd–Pt bond distances ranging from 2.91–3.42 Å. In the fourth Gd site, Gd is bonded in a 2-coordinate geometry to three Pt atoms. There are a spread of Gd–Pt bond distances ranging from 2.90–3.41 Å. In the fifth Gd site, Gd is bonded in a 2-coordinate geometry to two Pt atoms. There are one shorter (2.90 Å) and one longer (2.95 Å) Gd–Pt bond lengths. In the sixth Gd site, Gd is bonded in a 2-coordinate geometry to two Pt atoms. There are one shorter (2.91 Å) and one longer (2.95 Å) Gd–Pt bond lengths. In the seventh Gd site, Gd is bonded in a 2-coordinate geometry to two Pt atoms. There are one shorter (2.91 Å) and one longer (2.95 Å) Gd–Pt bond lengths. In the eighth Gd site, Gd is bonded in a 2-coordinate geometry to two Pt atoms. There are one shorter (2.90 Å) and one longer (2.95 Å) Gd–Pt bond lengths. In the ninth Gd site, Gd is bonded in a distorted bent 150 degrees geometry to two Pt atoms. There are one shorter (2.85 Å) and one longer (2.93 Å) Gd–Pt bond lengths. In the tenth Gd site, Gd is bonded in a distorted bent 150 degrees geometry to two Pt atoms. There are one shorter (2.85 Å) and one longer (2.94 Å) Gd–Pt bond lengths. In the eleventh Gd site, Gd is bonded in a distorted bent 150 degrees geometry to two Pt atoms. There are one shorter (2.84 Å) and one longer (2.93 Å) Gd–Pt bond lengths. In the twelfth Gd site, Gd is bonded in a distorted bent 150 degrees geometry to two Pt atoms. There are one shorter (2.86 Å) and one longer (2.93 Å) Gd–Pt bond lengths. There are four inequivalent Pt sites. In the first Pt site, Pt is bonded in a 6-coordinate geometry to seven Gd atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to seven Gd atoms. In the third Pt site, Pt is bonded in a 6-coordinate geometry to seven Gd atoms. In the fourth Pt site, Pt is bonded in a 6-coordinate geometry to seven Gd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SmSi3Pt5 by Materials Project

SmPt5Si3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Sm2+ is bonded in a 6-coordinate geometry to six Pt+1.20- atoms. There are a spread of Sm–Pt bond distances ranging from 3.10–3.19 Å. There are five inequivalent Pt+1.20- sites. In the first Pt+1.20- site, Pt+1.20- is bonded in a 4-coordinate geometry to two equivalent Sm2+ and four Si+1.33+ atoms. There are a spread of Pt–Si bond distances ranging from 2.39–2.58 Å. In the second Pt+1.20- site, Pt+1.20- is bonded in a 2-coordinate geometry to two equivalent Sm2+ and four Si+1.33+ atoms. There are a spread of Pt–Si bond distances ranging from 2.39–2.65 Å. In the third Pt+1.20- site, Pt+1.20- is bonded in a 6-coordinate geometry to two equivalent Sm2+ and four Si+1.33+ atoms. There are two shorter (2.44 Å) and two longer (2.65 Å) Pt–Si bond lengths. In the fourth Pt+1.20- site, Pt+1.20- is bonded in a 3-coordinate geometry to five Si+1.33+ atoms. There are a spread of Pt–Si bond distances ranging from 2.46–2.73 Å. In the fifth Pt+1.20- site, Pt+1.20- is bonded in a trigonal non-coplanar geometry to three equivalent Si+1.33+ atoms. There are one shorter (2.41 Å) and two longer (2.50 Å) Pt–Si bond lengths. There are three inequivalent Si+1.33+ sites. In the first Si+1.33+ site, Si+1.33+ is bonded in a 6-coordinate geometry to six Pt+1.20- atoms. In the second Si+1.33+ site, Si+1.33+ is bonded in a 7-coordinate geometry to seven Pt+1.20- atoms. In the third Si+1.33+ site, Si+1.33+ is bonded in a 7-coordinate geometry to seven Pt+1.20- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr23Mg4Pt7 by Materials Project

Pr23Pt7Mg4 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to three equivalent Mg and nine Pr atoms to form face-sharing MgPr9Mg3 cuboctahedra. All Mg–Mg bond lengths are 3.22 Å. There are a spread of Mg–Pr bond distances ranging from 3.50–3.71 Å. In the second Mg site, Mg is bonded to three Mg and nine Pr atoms to form a mixture of face and corner-sharing MgPr9Mg3 cuboctahedra. Both Mg–Mg bond lengths are 3.25 Å. There are a spread of Mg–Pr bond distances ranging from 3.49–3.75 Å. There are nine inequivalent Pr sites. In the first Pr site, Pr is bonded in a distorted bent 150 degrees geometry to two Mg and two equivalent Pt atoms. Both Pr–Pt bond lengths are 2.97 Å. In the second Pr site, Pr is bonded in a distorted T-shaped geometry to three Pt atoms. There are two shorter (3.01 Å) and one longer (3.08 Å) Pr–Pt bond lengths. In the third Pr site, Pr is bonded in a bent 150 degrees geometry to two equivalent Mg and two Pt atoms. There are one shorter (2.96 Å) and one longer (2.97 Å) Pr–Pt bond lengths. In the fourth Pr site, Pr is bonded in a 3-coordinate geometry to three Mg and three Pt atoms. There are one shorter (2.96 Å) and two longer (2.97 Å) Pr–Pt bond lengths. In the fifth Pr site, Pr is bonded in a 3-coordinate geometry to one Mg and two equivalent Pt atoms. Both Pr–Pt bond lengths are 3.74 Å. In the sixth Pr site, Pr is bonded in a 3-coordinate geometry to three equivalent Pt atoms. All Pr–Pt bond lengths are 2.99 Å. In the seventh Pr site, Pr is bonded in a distorted water-like geometry to one Mg and four Pt atoms. There are two shorter (2.92 Å) and two longer (3.66 Å) Pr–Pt bond lengths. In the eighth Pr site, Pr is bonded in a 4-coordinate geometry to two equivalent Mg and two Pt atoms. There are one shorter (3.58 Å) and one longer (3.73 Å) Pr–Pt bond lengths. In the ninth Pr site, Pr is bonded in a 3-coordinate geometry to three equivalent Mg and three equivalent Pt atoms. All Pr–Pt bond lengths are 2.97 Å. There are three inequivalent Pt sites. In the first Pt site, Pt is bonded in a 6-coordinate geometry to nine Pr atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to eight Pr atoms. In the third Pt site, Pt is bonded in a 6-coordinate geometry to nine Pr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd23Mg4Pt7 by Materials Project

Nd23Pt7Mg4 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to three Mg and nine Nd atoms to form a mixture of corner and face-sharing MgNd9Mg3 cuboctahedra. There are one shorter (3.22 Å) and two longer (3.25 Å) Mg–Mg bond lengths. There are a spread of Mg–Nd bond distances ranging from 3.45–3.72 Å. In the second Mg site, Mg is bonded to three equivalent Mg and nine Nd atoms to form face-sharing MgNd9Mg3 cuboctahedra. There are a spread of Mg–Nd bond distances ranging from 3.47–3.69 Å. There are nine inequivalent Nd sites. In the first Nd site, Nd is bonded in a distorted water-like geometry to one Mg and four Pt atoms. There are two shorter (2.90 Å) and two longer (3.61 Å) Nd–Pt bond lengths. In the second Nd site, Nd is bonded in a 3-coordinate geometry to three equivalent Pt atoms. All Nd–Pt bond lengths are 2.97 Å. In the third Nd site, Nd is bonded in a 3-coordinate geometry to three Mg and three Pt atoms. There are one shorter (2.94 Å) and two longer (2.95 Å) Nd–Pt bond lengths. In the fourth Nd site, Nd is bonded in a 3-coordinate geometry to three equivalent Mg and three equivalent Pt atoms. All Nd–Pt bond lengths are 2.94 Å. In the fifth Nd site, Nd is bonded in a distorted bent 150 degrees geometry to two Mg and two equivalent Pt atoms. Both Nd–Pt bond lengths are 2.94 Å. In the sixth Nd site, Nd is bonded in a bent 150 degrees geometry to two equivalent Mg and two Pt atoms. Both Nd–Pt bond lengths are 2.94 Å. In the seventh Nd site, Nd is bonded in a 3-coordinate geometry to one Mg and two equivalent Pt atoms. Both Nd–Pt bond lengths are 3.70 Å. In the eighth Nd site, Nd is bonded in a distorted T-shaped geometry to three Pt atoms. There are two shorter (2.98 Å) and one longer (3.06 Å) Nd–Pt bond lengths. In the ninth Nd site, Nd is bonded in a 4-coordinate geometry to two equivalent Mg and two Pt atoms. There are one shorter (3.58 Å) and one longer (3.70 Å) Nd–Pt bond lengths. There are three inequivalent Pt sites. In the first Pt site, Pt is bonded in a 6-coordinate geometry to nine Nd atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to nine Nd atoms. In the third Pt site, Pt is bonded in a 6-coordinate geometry to eight Nd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La23Cd4Pt7 by Materials Project

La23Pt7Cd4 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are nine inequivalent La sites. In the first La site, La is bonded in a distorted bent 150 degrees geometry to two Pt and two equivalent Cd atoms. There are one shorter (2.96 Å) and one longer (3.00 Å) La–Pt bond lengths. Both La–Cd bond lengths are 3.70 Å. In the second La site, La is bonded in a 3-coordinate geometry to three equivalent Pt atoms. All La–Pt bond lengths are 3.02 Å. In the third La site, La is bonded in a 3-coordinate geometry to two equivalent Pt and one Cd atom. Both La–Pt bond lengths are 3.71 Å. The La–Cd bond length is 3.52 Å. In the fourth La site, La is bonded in a 2-coordinate geometry to four Pt and one Cd atom. There are two shorter (2.94 Å) and two longer (3.71 Å) La–Pt bond lengths. The La–Cd bond length is 3.50 Å. In the fifth La site, La is bonded in a distorted bent 150 degrees geometry to two equivalent Pt and two Cd atoms. Both La–Pt bond lengths are 2.97 Å. There are one shorter (3.72 Å) and one longer (3.76 Å) La–Cd bond lengths. In the sixth La site, La is bonded in a 4-coordinate geometry to two Pt and two equivalent Cd atoms. There are one shorter (3.55 Å) and one longer (3.72 Å) La–Pt bond lengths. Both La–Cd bond lengths are 3.50 Å. In the seventh La site, La is bonded in a distorted T-shaped geometry to three Pt atoms. There are two shorter (3.04 Å) and one longer (3.16 Å) La–Pt bond lengths. In the eighth La site, La is bonded in a 3-coordinate geometry to three Pt and three Cd atoms. All La–Pt bond lengths are 2.99 Å. There are two shorter (3.60 Å) and one longer (3.65 Å) La–Cd bond lengths. In the ninth La site, La is bonded in a 3-coordinate geometry to three equivalent Pt and three equivalent Cd atoms. All La–Pt bond lengths are 3.00 Å. All La–Cd bond lengths are 3.59 Å. There are three inequivalent Pt sites. In the first Pt site, Pt is bonded in a 6-coordinate geometry to nine La atoms. In the second Pt site, Pt is bonded in a 6-coordinate geometry to nine La atoms. In the third Pt site, Pt is bonded in a 6-coordinate geometry to eight La atoms. There are two inequivalent Cd sites. In the first Cd site, Cd is bonded to nine La and three Cd atoms to form a mixture of distorted corner and face-sharing CdLa9Cd3 cuboctahedra. There are one shorter (3.27 Å) and two longer (3.29 Å) Cd–Cd bond lengths. In the second Cd site, Cd is bonded to nine La and three equivalent Cd atoms to form distorted face-sharing CdLa9Cd3 cuboctahedra.

36 MATERIALS SCIENCE↗