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At least 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Data-Driven Mapping of the Cesium Cadmium Bromide Phase Space Utilizing a Soft-Chemistry Approach

Soft-chemistry techniques provide a versatile approach to synthesizing inorganic materials under mild conditions, enabling access to compositions and structures that are challenging to achieve through traditional thermodynamically driven solid-state methods. However, these solution-based routes often result in phase competition, requiring precise control over reaction conditions to achieve selective product formation. While one-variable-at-a-time (OVAT) approaches have traditionally been used for phase selection, data-driven strategies are emerging as more efficient methods for navigating complex synthetic spaces. Ternary metal halides, such as cesium cadmium bromides (Cs–Cd–Br), are of growing interest due to their potential in wide and ultrawide band gap applications. Unlike the well-studied cesium lead halide phases, the compositional diversity and solution-based synthesis of ternary Cs–Cd–Br phases remain largely unexplored. This study systematically investigates the synthetic phase space of the Cs–Cd–Br system by constructing a data-driven phase map. Using a common set of precursors and a standardized experimental procedure, we successfully synthesize all four known Cs–Cd–Br phases—CsCdBr 3 , Cs 2 CdBr 4 , Cs 3 CdBr 5 , and Cs 7 Cd 3 Br 13 —each exhibiting distinct structures, morphologies, and optical properties. Our findings highlight the potential of soft-chemistry methods for expanding the library of ternary metal halides and provide key insights into the thermodynamic and kinetic factors governing phase formation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Cyclodextrin-Derived Porous Liquids Enabled by In Situ Solvation Shell Formation

Porous liquids (PLs) represent a unique platform for molecular separations by combining permanent porosity with liquid-phase mobility. However, it remains a formidable challenge to construct and stabilize PLs with sub-5 Å pores using readily available porous host and liquid media. Here, we report the construction of cyclodextrin (CD)-derived PLs enabled by in situ solvation shell formation. The acid–base neutralization reaction between CD and an organic base was leveraged to generate a thin ionic solvation shell around the CD host, effectively liquefying CD and preventing its segregation in the liquid base medium while preserving accessible molecular-scale cavities. Spectroscopic analysis, neutron scattering, density functional theory calculations, and molecular dynamics simulations collectively confirm the structural evolution and existence of abundant internal porosity in PLs. The unique architectures of CD-derived PLs enable highly selective encapsulation of fluorinated alkanes and significantly enhanced uptake of inert gases. This facile and generalizable strategy enables construction of high-quality PLs with engineered ultramicroporosity to facilitate molecular separations.

Cavities↗
DOE OSTI2022

Impact of dopant-induced band tails on optical spectra, charge carrier transport, and dynamics in single-crystal CdTe

Abstract Cadmium telluride (CdTe) semiconductors are used in thin-film photovoltaics, detectors, and other optoelectronic applications. For all technologies, higher efficiency and sensitivity are achieved with reduced charge carrier recombination. In this study, we use state-of-the-art CdTe single crystals and electro-optical measurements to develop a detailed understanding of recombination rate dependence on excitation and temperature in CdTe. We study recombination and carrier dynamics in high-resistivity (undoped) and arsenic (As)-doped CdTe by employing absorption, the Hall effect, time-resolved photoluminescence, and pump-probe in the 80–600 K temperature range. We report extraordinarily long lifetimes (30 µs) at low temperatures in bulk undoped CdTe. Temperature dependencies of carrier density and mobility reveal ionization of the main acceptors and donors as well as dominant scattering by ionized impurities. We also distinguish different recombination defects. In particular, shallow As Te and deep V Cd −As Cd acceptors were responsible for p-type conductivity. AX donors were responsible for electron capture, while nonradiative recombination centers (V Cd −As Te , As 2 precipitates), and native defects (V Cd −Te Cd ) were found to be dominant in p-type and n-type CdTe, respectively. Bimolecular and surface recombination rate temperature dependencies were also revealed, with bimolecular coefficient T −3/2 temperature dependence and 170 meV effective surface barrier, leading to an increase in surface recombination velocity at high temperatures and excitations. The results of this study allowed us to conclude that enhanced crucible rotation growth of As-doped CdTe is advantageous to As activation, leading to longer lifetimes and larger mobilities and open-circuit voltages due to lower absorption and trapping.

36 MATERIALS SCIENCE↗
DOE OSTI2025

The balance of orbital overlap and orbital energy in the activation of methane by actinide cations: insights from inductively coupled plasma tandem mass spectrometry

The actinides present a unique challenge to chemical theory. The classical view of covalent bonding is driven by the extent of spatial overlap of valence orbitals. Modern theory has expanded assessments of covalency to include considerations of orbital energy degeneracy to assess orbital energy mixing between metal and ligand valence orbitals. Actinide–ligand (An–L) bonding has more recently been described as a balance between orbital overlap and orbital energy mixing, where 5f and L valence orbital overlap decreases while energy mixing between An 5f and L valence orbitals increases across the series. To test these existing views, we employed inductively coupled plasma tandem mass spectrometry to examine the kinetic energy dependences of reactions of actinide cations, Th + –Am + , with methane. Further, this is the first experimental report of the energy dependences of methane activation reactions involving the cations of Pa, Np, Pu, and Am and the first experimental determination of transuranic An + –D, An + –CD 2 , An + –CD 3 , and An + –CD bond dissociation energies. The correlation of the measured An + –CD 2 bond energies with E p (6d 2 ) indicates that An + 6d orbitals are the dominant contributors in the An + –CD 2 bonds. Close examination of the relative reactivities of An + offers additional support that the balance of classical and modern views of molecular bonding may lie between Np + and Pu + and that the increased reactivity of Th + –Np + may be attributed to the increased spatial extension of the 5f orbitals whereas covalent An + bond formation may be more driven by the decreasing energies of the 5f orbitals across the actinide series.

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

Redshift-space distortions in simulations of the 21-cm signal from the cosmic dawn

ABSTRACT The 21-cm signal from the Cosmic Dawn (CD) is likely to contain large fluctuations, with the most extreme astrophysical models on the verge of being ruled out by observations from radio interferometers. It is therefore vital that we understand not only the astrophysical processes governing this signal, but also other inherent processes impacting the signal itself, and in particular line-of-sight effects. Using our suite of fully numerical radiative transfer simulations, we investigate the impact on the redshifted 21-cm from the CD from one of these processes, namely the redshift-space distortions (RSDs). When RSDs are added, the resulting boost to the power spectra makes the signal more or equally detectable for our models for all redshifts, further strengthening hopes that a power spectra measurement of the CD will be possible. RSDs lead to anisotropy in the signal at the beginning and end of the CD, but not while X-ray heating is underway. The inclusion of RSDs, however, decreases detectability of the non-Gaussianity of fluctuations from inhomogeneous X-ray heating as measured by the skewness and kurtosis. On the other hand, mock observations created from all our simulations that include telescope noise corresponding to 1000 h of observation with the Square Kilometre Array telescope show that we may be able to image the CD for all heating models considered and suggest RSDs dramatically boost fluctuations coming from the inhomogeneous Ly α background.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Dual-band selective circular dichroism in mid-infrared chiral metasurfaces

Most chiral metamaterials and metasurfaces are designed to operate in a single wavelength band and with a certain circular dichroism (CD) value. Here, mid-infrared chiral metasurface absorbers with selective CD in dual-wavelength bands are designed and demonstrated. The dual-band CD selectivity and tunability in the chiral metasurface absorbers are enabled by the unique design of a unit cell with two coupled rectangular bars. It is shown that the sign of CD in each wavelength band can be independently controlled and flipped by simply adjusting the geometric parameters, the width and the length, of the vertical rectangular bars. The mechanism of the dual-band CD selection in the chiral metasurface absorber is further revealed by studying the electric field and magnetic field distributions of the antibonding and bonding modes supported in the coupled bars under circularly polarized incident light. Furthermore, the chiral resonance wavelength can be continuously increased by scaling up the geometric parameters of the metasurface unit cell. The demonstrated results will contribute to the advance of future mid-infrared applications such as chiral molecular sensing, thermophotovoltaics, and optical communication.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Infrared phase-change chiral metasurfaces with tunable circular dichroism

Integrating phase-change materials in metasurfaces has emerged as a powerful strategy to realize optical devices with tunable electromagnetic responses. Here, phase-change chiral metasurfaces based on GST-225 material with the designed trapezoid-shaped resonators are demonstrated to achieve tunable circular dichroism (CD) responses in the infrared regime. The asymmetric trapezoid-shaped resonators are designed to support two chiral plasmonic resonances with opposite CD responses for realizing switchable CD between negative and positive values using the GST phase change from amorphous to crystalline. The electromagnetic field distributions of the chiral plasmonic resonant modes are analyzed to understand the chiroptical responses of the metasurface. Furthermore, the variations in the absorption spectrum and CD value for the metasurface as a function of the baking time during the GST phase transition are analyzed to reveal the underlying thermal tuning process of the metasurface. The demonstrated phase-change metasurfaces with tunable CD responses hold significant promise in enabling many applications in the infrared regime such as chiral sensing, encrypted communication, and thermal imaging.

42 ENGINEERING↗
DOE OSTI2024

Cadmium-Free QD Building Blocks for Human Centric Lighting

This project developed Cd-free quantum dot (QD) downconverters for efficacious human-centric lighting (HCL) light emitting diode (LED) devices. Solid state HCL devices address the lack of light in the cyan wavelength region (460-490 nm) in white LEDs by enhancing the melanopic daylight efficacy ratio (MDER) value. MDER is a metric that indicates the degree to which artificial lighting stimulates nonvisual biological processes in the retina responsible for regulating circadian rhythms compared with natural lighting. The peak sensitivity of melanopsin in the retina is at 479 nm, therefore artificial lighting which can fill the well-known “cyan gap” may improve human health. Due to the Restriction of Hazardous Substances (RoHS) regulations, cadmium-free core/shell/shell QDs are the primary targets for low toxicity, tunable downconverters. Cyan- and red-emitting core/shell/shell QDs were implemented in LED devices toward achieving a brightness of 210 lm/W at 4000 K, CRI 90, and MDER > 0.7. Synthetic development of Cd-free materials yielded cyan InP/ZnS QDs with a photoluminescence quantum yield (PLQY) of ~60% between 480-490 nm, and red InP/ZnSe/(ZnSeS)/ZnS QDs reaching ~80% PLQY at 620-630 nm. We successfully demonstrated that the inclusion of cyan QDs increased the MDER value to ≥0.7, but the brightness of the HCL LED devices was hindered due to low PLQY values. However, upon substitution of the Cd-free cyan QD with a low-Cd QD with >90% PLQY, brightness improved by 25% over the Cd-free device to 179 lm/W. Despite the technical obstacles remaining toward improving emission characteristics and stability of QDs under high flux, we have confirmed the promise of narrow, tunable QD emitters in SSL packages toward the goal of healthy, human-centric lighting.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Genome-Wide Association Study Reveals Complex Genetic Architecture of Cadmium and Mercury Accumulation and Tolerance Traits in Medicago truncatula

Heavy metals are an increasing problem due to contamination from human sources that and can enter the food chain by being taken up by plants. Understanding the genetic basis of accumulation and tolerance in plants is important for reducing the uptake of toxic metals in crops and crop relatives, as well as for removing heavy metals from soils by means of phytoremediation. Following exposure of Medicago truncatula seedlings to cadmium (Cd) and mercury (Hg), we conducted a genome-wide association study using relative root growth (RRG) and leaf accumulation measurements. Cd and Hg accumulation and RRG had heritability ranging 0.44 – 0.72 indicating high genetic diversity for these traits. The Cd and Hg trait associations were broadly distributed throughout the genome, indicated the traits are polygenic and involve several quantitative loci. For all traits, candidate genes included several membrane associated ATP-binding cassette transporters, P-type ATPase transporters, oxidative stress response genes, and stress related UDP-glycosyltransferases. The P-type ATPase transporters and ATP-binding cassette protein-families have roles in vacuole transport of heavy metals, and our findings support their wide use in physiological plant responses to heavy metals and abiotic stresses. We also found associations between Cd RRG with the genes CAX3 and PDR3, two linked adjacent genes, and leaf accumulation of Hg associated with the genes NRAMP6 and CAX9. When plant genotypes with the most extreme phenotypes were compared, we found significant divergence in genomic regions using population genomics methods that contained metal transport and stress response gene ontologies. Several of these genomic regions show high linkage disequilibrium (LD) among candidate genes suggesting they have evolved together. Minor allele frequency (MAF) and effect size of the most significant SNPs was negatively correlated with large effect alleles being most rare. This is consistent with purifying selection against alleles that increase toxicity and abiotic stress. Conversely, the alleles with large affect that had higher frequencies that were associated with the exclusion of Cd and Hg. Overall, macroevolutionary conservation of heavy metal and stress response genes is important for improvement of forage crops by harnessing wild genetic variants in gene banks such as the Medicago HapMap collection.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

A Single Amino Acid Change in Nramp6 from Sedum Alfredii Hance Affects Cadmium Accumulation

SaNramp6 in Sedum alfredii encodes a membrane-localized metal transporter. We isolated the SaNramp6h allele from the hyperaccumulating ecotype (HE) of S. alfredii . When this allele was expressed in transgenic yeast and Arabidopsis thaliana , it enhanced their cadmium (Cd) sensitivity by increased Cd transport and accumulation. We isolated another allele, SaNramp6n , from a nonhyperaccumulating ecotype (NHE) of S. alfredii . Amino acid sequence comparisons revealed three amino acid differences between SaNramp6h and SaNramp6n. We investigated the Cd transport activity of the Nramp6 allele, and determined which residues are essential for the transport activity. We conducted structure-function analyses of SaNramp6 based on site-directed mutagenesis and functional assays of the mutants in yeast and Arabidopsis . The three residues that differed between SaNramp6h and SaNramp6n were mutated. Only the L157P mutation of SaNramp6h impaired Cd transport. The other mutations, S218N and T504A, did not affect the transport activity of SaNramp6h, indicating that these residues are not essential for metal selectivity. Transgenic plants overexpressing SaNramp6h L157P showed altered metal accumulation in shoots and roots. Our results suggest that the conserved site L157 is essential for the high metal transport activity of SaNramp6h. This information may be useful for limiting or increasing Cd transport by other plant natural resistance associated macrophage protein (NRAMP) proteins.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Preparation and Characterization of Inclusion Complexes of β-Cyclodextrin and Phenolics from Wheat Bran by Combination of Experimental and Computational Techniques

Bitterness often associated with whole wheat products may be related to phenolics in the bran. Cyclodextrins (CDs) are known to form inclusion complexes. The objective was to form inclusion complexes between β-CD and wheat phenolics. Pure phenolic acids (trans-ferulic acid (FA), caffeic acid (CA), and p-coumaric acid (CO)) and phenolic acids from wheat bran were used to investigate complex formation potential. Complexes were characterized by spectroscopy techniques, and a computational and molecular modeling study was carried out. The relative amount of complex formation between β-CD and wheat bran extract was CA > CO > FA. The phenolic compounds formed inclusion complexes with β-CDs by non-covalent bonds. The quantum-mechanical calculations supported the experimental results. The most stable complex was CO/β-CD complex. The ΔH value for CO/β-CD complex was -11.72 kcal/mol and was about 3 kcal/mol more stable than the other complexes. The QSPR model showed good correlation between binding energy and 1H NMR shift for the H5 signal. This research shows that phenolics and β-CD inclusion complexes could be utilized to improve the perception of whole meal food products since inclusion complexes have the potential to mask the bitter flavor and enhance the stability of the phenolics in wheat bran.

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

Materials Data on Cd4SiSe6 by Materials Project

Cd4SiSe6 is Chalcostibite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Cd–Se bond distances ranging from 2.70–3.48 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent CdSe4 tetrahedra and corners with two equivalent SiSe4 tetrahedra. There are a spread of Cd–Se bond distances ranging from 2.68–2.73 Å. In the third Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent CdSe4 tetrahedra and corners with two equivalent SiSe4 tetrahedra. There are a spread of Cd–Se bond distances ranging from 2.68–2.76 Å. In the fourth Cd2+ site, Cd2+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Cd–Se bond distances ranging from 2.69–2.77 Å. Si4+ is bonded to four Se2- atoms to form SiSe4 tetrahedra that share corners with four CdSe4 tetrahedra. There are a spread of Si–Se bond distances ranging from 2.28–2.30 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Cd2+ atoms to form distorted corner-sharing SeCd4 trigonal pyramids. In the second Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to two Cd2+ and one Si4+ atom. In the third Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Cd2+ and one Si4+ atom. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Cd2+ and one Si4+ atom. In the fifth Se2- site, Se2- is bonded to four Cd2+ atoms to form corner-sharing SeCd4 tetrahedra. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to two Cd2+ and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd4GeSe6 by Materials Project

Cd4GeSe6 is Chalcostibite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent GeSe4 tetrahedra and corners with five CdSe4 tetrahedra. There are a spread of Cd–Se bond distances ranging from 2.70–2.76 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form distorted CdSe4 tetrahedra that share corners with two equivalent GeSe4 tetrahedra and corners with six CdSe4 tetrahedra. There are a spread of Cd–Se bond distances ranging from 2.70–2.77 Å. In the third Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent GeSe4 tetrahedra and corners with five CdSe4 tetrahedra. There are a spread of Cd–Se bond distances ranging from 2.70–2.73 Å. In the fourth Cd2+ site, Cd2+ is bonded in a 4-coordinate geometry to five Se2- atoms. There are a spread of Cd–Se bond distances ranging from 2.71–3.54 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with six CdSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.36–2.39 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Cd2+ atoms to form corner-sharing SeCd4 tetrahedra. In the second Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Cd2+ and one Ge4+ atom. In the third Se2- site, Se2- is bonded to four Cd2+ atoms to form corner-sharing SeCd4 tetrahedra. In the fourth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three Cd2+ and one Ge4+ atom. In the fifth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to two Cd2+ and one Ge4+ atom. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to two Cd2+ and one Ge4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd4SiS6 by Materials Project

Cd4SiS6 is Chalcostibite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Cd–S bond distances ranging from 2.56–2.66 Å. In the second Cd2+ site, Cd2+ is bonded to four S2- atoms to form CdS4 tetrahedra that share corners with two equivalent CdS4 tetrahedra and corners with two equivalent SiS4 tetrahedra. There are a spread of Cd–S bond distances ranging from 2.57–2.61 Å. In the third Cd2+ site, Cd2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Cd–S bond distances ranging from 2.57–3.30 Å. In the fourth Cd2+ site, Cd2+ is bonded to four S2- atoms to form CdS4 tetrahedra that share corners with two equivalent CdS4 tetrahedra and corners with two equivalent SiS4 tetrahedra. There are a spread of Cd–S bond distances ranging from 2.56–2.64 Å. Si4+ is bonded to four S2- atoms to form SiS4 tetrahedra that share corners with four CdS4 tetrahedra. There are a spread of Si–S bond distances ranging from 2.12–2.15 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to two Cd2+ and one Si4+ atom. In the second S2- site, S2- is bonded in a trigonal non-coplanar geometry to two Cd2+ and one Si4+ atom. In the third S2- site, S2- is bonded to four Cd2+ atoms to form corner-sharing SCd4 tetrahedra. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to three Cd2+ and one Si4+ atom. In the fifth S2- site, S2- is bonded in a 3-coordinate geometry to two Cd2+ and one Si4+ atom. In the sixth S2- site, S2- is bonded to four Cd2+ atoms to form corner-sharing SCd4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd2H3ClO3 by Materials Project

Cd2H3O3Cl crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to five O2- and one Cl1- atom to form distorted edge-sharing CdClO5 octahedra. There are a spread of Cd–O bond distances ranging from 2.30–2.37 Å. The Cd–Cl bond length is 2.77 Å. In the second Cd2+ site, Cd2+ is bonded to four O2- and two equivalent Cl1- atoms to form distorted edge-sharing CdCl2O4 octahedra. All Cd–O bond lengths are 2.28 Å. Both Cd–Cl bond lengths are 2.89 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three Cd2+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Cd2+ and one H1+ atom. Cl1- is bonded in a 3-coordinate geometry to three Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiCd4Ge5HO15 by Materials Project

LiCd4Ge5HO15 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.98–2.12 Å. There are four inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six GeO4 tetrahedra and edges with three CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.28–2.44 Å. In the second Cd2+ site, Cd2+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Cd–O bond distances ranging from 2.22–3.00 Å. In the third Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six GeO4 tetrahedra and edges with three CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.26–2.40 Å. In the fourth Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six GeO4 tetrahedra and edges with four CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.30–2.45 Å. There are five inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with three CdO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–64°. There are a spread of Ge–O bond distances ranging from 1.74–1.82 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four CdO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Ge–O bond distances ranging from 1.74–1.82 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with three CdO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–65°. There are a spread of Ge–O bond distances ranging from 1.75–1.80 Å. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four CdO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–65°. There are a spread of Ge–O bond distances ranging from 1.76–1.79 Å. In the fifth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four CdO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–64°. There are a spread of Ge–O bond distances ranging from 1.75–1.81 Å. H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.07 Å) and one longer (1.42 Å) H–O bond length. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cd2+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Cd2+, one Ge4+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Cd2+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two Cd2+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded to one Li1+, two Cd2+, and one Ge4+ atom to form distorted corner-sharing OLiCd2Ge tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Cd2+, one Ge4+, and one H1+ atom. In the seventh O2- site, O2- is bonded to three Cd2+ and one Ge4+ atom to form distorted corner-sharing OCd3Ge tetrahedra. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cd2+ and one Ge4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Cd2+ and two Ge4+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cd2+ and two Ge4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+ and two Ge4+ atoms. In the twelfth O2- site, O2- is bonded to three Cd2+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing OCd3Ge tetrahedra. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+ and two Ge4+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Cd2+ and one Ge4+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Cd2+ and one Ge4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd4As2I3 by Materials Project

Cd4As2I3 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded in a 6-coordinate geometry to two As+2.50- and four equivalent I1- atoms. There are one shorter (2.62 Å) and one longer (2.65 Å) Cd–As bond lengths. There are a spread of Cd–I bond distances ranging from 3.06–3.82 Å. In the second Cd2+ site, Cd2+ is bonded in a rectangular see-saw-like geometry to one As+2.50- and three equivalent I1- atoms. The Cd–As bond length is 2.61 Å. All Cd–I bond lengths are 2.97 Å. There are two inequivalent As+2.50- sites. In the first As+2.50- site, As+2.50- is bonded to four Cd2+ atoms to form corner-sharing AsCd4 trigonal pyramids. In the second As+2.50- site, As+2.50- is bonded to three equivalent Cd2+ and one As+2.50- atom to form corner-sharing AsCd3As tetrahedra. The As–As bond length is 2.46 Å. I1- is bonded in a 3-coordinate geometry to five Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd2As3I by Materials Project

Cd2As3I crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to three As1- and two equivalent I1- atoms to form distorted CdAs3I2 trigonal bipyramids that share corners with two equivalent AsCd2As2 tetrahedra, corners with four equivalent CdAs3I2 trigonal bipyramids, and corners with four AsCd2As2 trigonal pyramids. There are a spread of Cd–As bond distances ranging from 2.70–2.79 Å. There are one shorter (3.04 Å) and one longer (3.51 Å) Cd–I bond lengths. In the second Cd2+ site, Cd2+ is bonded in a 5-coordinate geometry to three As1- and two equivalent I1- atoms. There are two shorter (2.70 Å) and one longer (2.80 Å) Cd–As bond lengths. There are one shorter (3.05 Å) and one longer (3.51 Å) Cd–I bond lengths. There are three inequivalent As1- sites. In the first As1- site, As1- is bonded to two equivalent Cd2+ and two As1- atoms to form distorted AsCd2As2 trigonal pyramids that share corners with three equivalent AsCd2As2 tetrahedra, corners with three equivalent CdAs3I2 trigonal bipyramids, and corners with three AsCd2As2 trigonal pyramids. There are one shorter (2.46 Å) and one longer (2.48 Å) As–As bond lengths. In the second As1- site, As1- is bonded to two Cd2+ and two As1- atoms to form distorted AsCd2As2 tetrahedra that share corners with two equivalent CdAs3I2 trigonal bipyramids and corners with six AsCd2As2 trigonal pyramids. The As–As bond length is 2.48 Å. In the third As1- site, As1- is bonded to two equivalent Cd2+ and two As1- atoms to form distorted AsCd2As2 trigonal pyramids that share corners with three equivalent AsCd2As2 tetrahedra, a cornercorner with one CdAs3I2 trigonal bipyramid, and corners with three AsCd2As2 trigonal pyramids. I1- is bonded in a distorted rectangular see-saw-like geometry to four Cd2+ atoms.

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