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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Cs(BI)6 by Materials Project

Cs(BI)6 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Cs sites. In the first Cs site, Cs is bonded in a 6-coordinate geometry to six I atoms. There are three shorter (4.03 Å) and three longer (4.06 Å) Cs–I bond lengths. In the second Cs site, Cs is bonded to twelve I atoms to form distorted edge-sharing CsI12 cuboctahedra. There are a spread of Cs–I bond distances ranging from 4.09–4.30 Å. There are four inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to five B and one I atom. There is two shorter (1.79 Å) and three longer (1.80 Å) B–B bond length. The B–I bond length is 2.19 Å. In the second B site, B is bonded in a distorted single-bond geometry to five B and one I atom. There is four shorter (1.79 Å) and one longer (1.80 Å) B–B bond length. The B–I bond length is 2.18 Å. In the third B site, B is bonded in a distorted single-bond geometry to five B and one I atom. Both B–B bond lengths are 1.80 Å. The B–I bond length is 2.18 Å. In the fourth B site, B is bonded in a distorted single-bond geometry to five B and one I atom. Both B–B bond lengths are 1.80 Å. The B–I bond length is 2.19 Å. There are four inequivalent I sites. In the first I site, I is bonded in a single-bond geometry to one Cs and one B atom. In the second I site, I is bonded in a distorted single-bond geometry to two Cs and one B atom. In the third I site, I is bonded in a distorted single-bond geometry to two equivalent Cs and one B atom. In the fourth I site, I is bonded in a distorted single-bond geometry to one Cs and one B atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Multiple Lattice Instabilities and Complex Ground State in Cs 2 Ag Bi Br 6

Metal-halide perovskites (MHPs) are attracting considerable interest for optoelectronic applications, with Cs 2 Ag Bi Br 6 one of the main contenders among lead-free systems. Cs 2 Ag Bi Br 6 crystallizes in a nominally double-perovskite structure, but exhibits a soft lattice with large atomic fluctuations characteristic of MHPs. While crucial to understand electron-phonon and phonon-phonon couplings, the spatiotemporal correlations of these fluctuations remain largely unknown. Here, we reveal these correlations using comprehensive neutron and x-ray scattering measurements on Cs 2 Ag Bi Br 6 single crystals, complemented with first-principles simulations augmented with machine-learned neural-network potentials. We report the discovery of an unexpected complex modulated ground-state structure containing several hundred atoms, arising from a soft-phonon instability of the low-temperature tetragonal phase. Further, our experiments and simulations both reveal extensive correlated two-dimensional fluctuations of Br octahedra at finite temperature, arising from soft optic phonons that are strongly broadened by anhamonicity, reflecting very shallow potential wells. These results provide new insights into the atomic structure and fluctuations in MHPs, critical to understand and control their thermal and optoelectronic properties. Published by the American Physical Society 2024

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Materials Data on Cs7(In2Bi3)2 by Materials Project

Cs7(In2Bi3)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are fourteen inequivalent Cs sites. In the first Cs site, Cs is bonded in a 3-coordinate geometry to three In and six Bi atoms. There are a spread of Cs–In bond distances ranging from 3.80–4.26 Å. There are a spread of Cs–Bi bond distances ranging from 3.94–4.38 Å. In the second Cs site, Cs is bonded in a 6-coordinate geometry to six Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.92–4.31 Å. In the third Cs site, Cs is bonded in a 3-coordinate geometry to one In and five Bi atoms. The Cs–In bond length is 4.15 Å. There are a spread of Cs–Bi bond distances ranging from 3.90–4.64 Å. In the fourth Cs site, Cs is bonded in a 6-coordinate geometry to one In and five Bi atoms. The Cs–In bond length is 4.13 Å. There are a spread of Cs–Bi bond distances ranging from 4.03–4.37 Å. In the fifth Cs site, Cs is bonded in a 6-coordinate geometry to six Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.87–4.27 Å. In the sixth Cs site, Cs is bonded in a 7-coordinate geometry to one In and six Bi atoms. The Cs–In bond length is 3.84 Å. There are a spread of Cs–Bi bond distances ranging from 3.87–4.17 Å. In the seventh Cs site, Cs is bonded in a 4-coordinate geometry to five Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.85–4.45 Å. In the eighth Cs site, Cs is bonded in a 6-coordinate geometry to three In and six Bi atoms. There are a spread of Cs–In bond distances ranging from 3.92–4.37 Å. There are a spread of Cs–Bi bond distances ranging from 3.95–4.25 Å. In the ninth Cs site, Cs is bonded in a 2-coordinate geometry to two In and six Bi atoms. There are one shorter (3.93 Å) and one longer (4.16 Å) Cs–In bond lengths. There are a spread of Cs–Bi bond distances ranging from 3.86–4.42 Å. In the tenth Cs site, Cs is bonded in a 9-coordinate geometry to three In and six Bi atoms. There are a spread of Cs–In bond distances ranging from 3.93–4.13 Å. There are a spread of Cs–Bi bond distances ranging from 3.93–4.20 Å. In the eleventh Cs site, Cs is bonded in a 7-coordinate geometry to one In and six Bi atoms. The Cs–In bond length is 4.21 Å. There are a spread of Cs–Bi bond distances ranging from 4.05–4.30 Å. In the twelfth Cs site, Cs is bonded in a 5-coordinate geometry to one In and four Bi atoms. The Cs–In bond length is 4.10 Å. There are a spread of Cs–Bi bond distances ranging from 4.02–4.24 Å. In the thirteenth Cs site, Cs is bonded in a 4-coordinate geometry to one In and six Bi atoms. The Cs–In bond length is 3.88 Å. There are a spread of Cs–Bi bond distances ranging from 3.92–4.56 Å. In the fourteenth Cs site, Cs is bonded in a 6-coordinate geometry to one In and five Bi atoms. The Cs–In bond length is 4.12 Å. There are a spread of Cs–Bi bond distances ranging from 3.91–4.37 Å. There are eight inequivalent In sites. In the first In site, In is bonded in a 4-coordinate geometry to two Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 2.98–3.10 Å. In the second In site, In is bonded in a 4-coordinate geometry to three Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 3.05–3.10 Å. In the third In site, In is bonded in a 3-coordinate geometry to three Cs, one In, and three Bi atoms. The In–In bond length is 3.03 Å. There are a spread of In–Bi bond distances ranging from 3.03–3.14 Å. In the fourth In site, In is bonded in a 4-coordinate geometry to two Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 3.02–3.09 Å. In the fifth In site, In is bonded in a 3-coordinate geometry to four Cs, one In, and three Bi atoms. The In–In bond length is 3.06 Å. There are a spread of In–Bi bond distances ranging from 3.05–3.15 Å. In the sixth In site, In is bonded in a 4-coordinate geometry to one Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 3.03–3.11 Å. In the seventh In site, In is bonded in a 5-coordinate geometry to one Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 2.99–3.08 Å. In the eighth In site, In is bonded in a 6-coordinate geometry to two Cs and four Bi atoms. There are a spread of In–Bi bond distances ranging from 2.96–3.15 Å. There are twelve inequivalent Bi sites. In the first Bi site, Bi is bonded in a 10-coordinate geometry to nine Cs and one In atom. In the second Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the third Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the fourth Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two In atoms. In the fifth Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two In atoms. In the sixth Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the seventh Bi site, Bi is bonded in a 10-coordinate geometry to five Cs and three In atoms. In the eighth Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the ninth Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two In atoms. In the tenth Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the eleventh Bi site, Bi is bonded in a 9-coordinate geometry to six Cs and three In atoms. In the twelfth Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Exploring Cs 2 AgIn x Bi 1− x Cl 6 double perovskites for optoelectronics: insights from theoretical and photophysical approaches

Lead-free halide double perovskites (HDPs) have become attractive materials for optoelectronic applications owing to their nontoxicity, structural stability, and germane photoelectric properties. In this work, we report the synthesis of high-quality In-alloyed Cs 2 AgIn x Bi (1−x) Cl 6 nanocrystals (NCs) using the antisolvent recrystallization method and comprehensively investigate the effects of In alloying on the structural, morphological, optoelectronic, and temperature-dependent photoluminescence (TDPL) properties using the state-of-the-art experimental and computational tools. Both XRD and Raman spectroscopy analyses confirmed the synthesis of highly crystalline Cs 2 AgIn x Bi (1−x) Cl 6 materials, which exhibited cubic morphology, as confirmed by TEM analysis. Room-temperature photoluminescence (PL) measurements revealed a drastic increase in the intensity above 75% In concentration with dual emission, whereas the time-resolved PL (TR-PL) results show an increase in the average lifetime values with an increase in In content, suggesting that the materials have excellent optical properties and hence are suitable candidates for optoelectronics. The TDPL measurements revealed the smallest Huang–Rhys factor (18.6) for the Cs 2 AgIn x Bi (1−x) Cl 6 (x = 0.9) sample, indicating weak exciton–phonon coupling in this composition. When deployed in the fabrication of a photodetector device, the Cs 2 AgIn x Bi (1−x) Cl 6 (x = 0.9) sample exhibited significantly enhanced photoresponsivity and a faster response time, confirming its potential for photodetector applications. Complementary DFT calculations showed that In alloying modifies the band structure of Cs 2 AgIn x Bi (1−x) Cl 6 . Our results provide valuable insights for designing multifunctional Cs 2 AgIn x Bi (1−x) Cl 6 -based materials for next-generation energy and optoelectronic devices.

14 SOLAR ENERGY↗
DOE OSTI2020

Tunable Perovskite-Derived Bismuth Halides: Cs 3 Bi 2 (Cl 1– x I x ) 9

Bismuth-based perovskites are of interest as safer alternatives to lead-based optoelectronic materials. Prior studies have reported on the compounds Cs 3 Bi 2 Cl 9 , Cs 3 Bi 2 I 9 , and Cs 3 Bi 2 Cl 3 I 6 . Here we examine a range of compounds of the formula Cs 3 Bi 2 (Cl 1–x I x ) 9 , where x takes values from 0.09 to 0.52. Powder and single-crystal X-ray diffraction were used to determine that all of these compounds adopt the layered vacancy-ordered perovskite structure observed for Cs 3 Bi 2 Cl 3 I 6 , which is also the high-temperature phase of Cs 3 Bi 2 Cl 9 . We find that, even with very small iodine incorporation, the structure is switched to that of Cs 3 Bi 2 Cl 3 I 6 , with I atoms displaying a distinct preference for the capping sites on the BiX 6 octahedra. Optical absorption spectroscopy was employed to study the evolution of optical properties of these materials, and this is complemented by density functional theory electronic structure calculations. Finally, three main absorption features were observed for these compounds, and with increasing x, the lowest-energy features are red-shifted.

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

Materials Data on CsBi by Materials Project

CsBi is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Cs sites. In the first Cs site, Cs is bonded in a 6-coordinate geometry to six Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.90–4.32 Å. In the second Cs site, Cs is bonded in a 7-coordinate geometry to seven Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.92–4.59 Å. In the third Cs site, Cs is bonded in a 7-coordinate geometry to seven Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.92–4.41 Å. In the fourth Cs site, Cs is bonded in a 6-coordinate geometry to six Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.88–4.33 Å. There are four inequivalent Bi sites. In the first Bi site, Bi is bonded in a 8-coordinate geometry to six Cs and two equivalent Bi atoms. There are one shorter (3.06 Å) and one longer (3.08 Å) Bi–Bi bond lengths. In the second Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two equivalent Bi atoms. In the third Bi site, Bi is bonded in a 8-coordinate geometry to six Cs and two equivalent Bi atoms. There are one shorter (3.07 Å) and one longer (3.09 Å) Bi–Bi bond lengths. In the fourth Bi site, Bi is bonded in a 9-coordinate geometry to seven Cs and two equivalent Bi atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Bi2 by Materials Project

Bi2Cs3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Cs sites. In the first Cs site, Cs is bonded in a 6-coordinate geometry to six equivalent Bi atoms. There are a spread of Cs–Bi bond distances ranging from 4.15–4.27 Å. In the second Cs site, Cs is bonded in a 6-coordinate geometry to six equivalent Bi atoms. There are a spread of Cs–Bi bond distances ranging from 3.95–4.30 Å. Bi is bonded in a 10-coordinate geometry to nine Cs and one Bi atom. The Bi–Bi bond length is 2.99 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Octahedral Distortion and Excitonic Behavior of Cs 3 Bi 2 Br 9 Halide Perovskite at Low Temperature

The metal halide ionic octahedron, represented as [MX 6 ] $n$- (M = metal cation, X = halide anion), serves as the basic structural unit in halide perovskites and plays a crucial role in determining their optoelectronic and chemical properties. Thus, it is possible to correlate the responses of metal halide perovskites to various environmental stimuli with the dynamic behaviors of the [MX 6 ] $n$- octahedra. In this study, with the temperature-dependent single-crystal X ray diffraction (SCXRD) measurements on Cs 3 Bi 2 Br 9 2D halide perovskites, we can identify two classes of distortions through the lowering of temperature: intraoctahedral distortion, which is the off-centering of Bi 3+ cation within a [BiBr 6 ] 3– octahedron due to the Bi 3+ 6s 2 lone pair electrons, and interoctahedral distortion, which is the collective misalignments among the [BiBr 6 ] 3– building blocks. Free exciton (FE) and self-trapped exciton (STE) models are used to study the relationship between the distortion of octahedra in Cs 3 Bi 2 Br 9 and the corresponding changes in its optoelectronic properties, which transform from dominating blue emission above 100 K to red emission at 4 K. In conclusion, this work provides new insights into the excitonic behaviors of perovskites and suggests a possibility that we can design and rationalize the optical properties of halide perovskites by regulating the environmental stimuli based on the knowledge of behaviors of the individual [MX 6 ] $n$- building blocks.

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

Magnetizing lead-free halide double perovskites

Spintronics holds great potential for next-generation high-speed and low–power consumption information technology. Recently, lead halide perovskites (LHPs), which have gained great success in optoelectronics, also show interesting magnetic properties. However, the spin-related properties in LHPs originate from the spin-orbit coupling of Pb, limiting further development of these materials in spintronics. Here, we demonstrate a new generation of halide perovskites, by alloying magnetic elements into optoelectronic double perovskites, which provide rich chemical and structural diversities to host different magnetic elements. In our iron-alloyed double perovskite, Cs 2 Ag(Bi:Fe)Br 6 , Fe 3+ replaces Bi 3+ and forms FeBr 6 clusters that homogenously distribute throughout the double perovskite crystals. Furthermore, we observe a strong temperature-dependent magnetic response at temperatures below 30 K, which is tentatively attributed to a weak ferromagnetic or antiferromagnetic response from localized regions. We anticipate that this work will stimulate future efforts in exploring this simple yet efficient approach to develop new spintronic materials based on lead-free double perovskites.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs2Bi2Pd by Materials Project

Cs2PdBi2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Cs sites. In the first Cs site, Cs is bonded in a 6-coordinate geometry to six equivalent Bi atoms. There are two shorter (3.98 Å) and four longer (4.39 Å) Cs–Bi bond lengths. In the second Cs site, Cs is bonded in a 8-coordinate geometry to two equivalent Pd and six equivalent Bi atoms. Both Cs–Pd bond lengths are 3.46 Å. There are two shorter (4.01 Å) and four longer (4.14 Å) Cs–Bi bond lengths. Pd is bonded to two equivalent Cs and four equivalent Bi atoms to form distorted face-sharing PdCs2Bi4 octahedra. All Pd–Bi bond lengths are 2.79 Å. Bi is bonded in a 4-coordinate geometry to six Cs, two equivalent Pd, and one Bi atom. The Bi–Bi bond length is 2.99 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs2Bi4Se7 by Materials Project

Cs2Bi4Se7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.58–3.91 Å. In the second Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.61–3.84 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 4–7°. There are a spread of Bi–Se bond distances ranging from 2.83–3.19 Å. In the second Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 7°. There are a spread of Bi–Se bond distances ranging from 2.89–3.08 Å. In the third Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 4–11°. There are a spread of Bi–Se bond distances ranging from 2.82–3.22 Å. In the fourth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are a spread of Bi–Se bond distances ranging from 2.87–3.09 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to three Cs1+ and three equivalent Bi3+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Cs1+ and two equivalent Bi3+ atoms. In the third Se2- site, Se2- is bonded to two equivalent Cs1+ and three Bi3+ atoms to form SeCs2Bi3 square pyramids that share a cornercorner with one SeBi6 octahedra, corners with six SeCs2Bi3 trigonal bipyramids, edges with four SeCs3Bi3 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two SeCs2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°. In the fourth Se2- site, Se2- is bonded to three Cs1+ and three Bi3+ atoms to form distorted SeCs3Bi3 octahedra that share corners with two equivalent SeBi6 octahedra, corners with five SeCs2Bi3 trigonal bipyramids, edges with five SeBi6 octahedra, and edges with two equivalent SeCs2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 6°. In the fifth Se2- site, Se2- is bonded to two equivalent Cs1+ and three Bi3+ atoms to form distorted SeCs2Bi3 trigonal bipyramids that share corners with three SeBi6 octahedra, corners with four equivalent SeCs2Bi3 square pyramids, an edgeedge with one SeCs2Bi3 square pyramid, and edges with four SeCs2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 2–41°. In the sixth Se2- site, Se2- is bonded to one Cs1+ and four Bi3+ atoms to form SeCsBi4 trigonal bipyramids that share corners with three equivalent SeCs3Bi3 octahedra, corners with two equivalent SeCs2Bi3 square pyramids, corners with two equivalent SeCsBi4 trigonal bipyramids, edges with two equivalent SeBi6 octahedra, an edgeedge with one SeCs2Bi3 square pyramid, and edges with two equivalent SeCs2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 8–34°. In the seventh Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share corners with two equivalent SeCs3Bi3 octahedra, a cornercorner with one SeCs2Bi3 square pyramid, a cornercorner with one SeCs2Bi3 trigonal bipyramid, edges with seven SeCs3Bi3 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two equivalent SeCsBi4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 6°.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Connectivity-Dependent Exciton–Phonon Coupling in Cesium Bismuth Halide Quantum Dots

Metal halide octahedra form the fundamental functional building blocks of metal halide perovskites, dictating their structures, optical properties, electronic structures, and dynamics. Here, in this study, we show that the connectivity of bismuth halide octahedra in Cs 3 Bi 2 Br 9 and Cs 3 Bi 2 I 9 quantum dots (QDs) changes with different halide elements. We use first-principles calculations to reveal the key role of the connectivity of bismuth halide octahedra on the wave function symmetry, Huang-Rhys factor, and exciton-phonon interaction strength. Following QD synthesis via a ligand-mediated transport method, the effect of connectivity is verified with transient absorption spectroscopy, where we contrast Cs 3 Bi 2 Br 9 and Cs 3 Bi 2 I 9 QD exciton dynamics. In photoexcited Cs 3 Bi 2 I 9 QDs, phonons related to the vibrational motions of face-sharing [BiI 6 ] 3- bioctahedra couple strongly to the electronic state and drive rapid carrier relaxation. Equivalent signals are not observed for photoexcited Cs 3 Bi 2 Br 9 QDs, implying a lack of phonon involvement in band-edge absorption and subsequent exciton relaxation. Our findings suggest that structural engineering can effectively tune the exciton-phonon coupling and therefore influence exciton relaxation and recombination in perovskite nanomaterials.

TDDFT↗
DOE OSTI2022

Spin and charge density waves in quasi-one-dimensional KMn 6 Bi 5

The recent observation that pressure could suppress antiferromagnetic (AFM) order in quasi-one-dimensional AMn 6 Bi 5 Mn-cluster chain materials (A=Na, K, Rb, and Cs) and lead to a superconducting dome offers an alternative Mn-based class of materials with which to study unconventional superconductivity. Using neutron diffraction, we elucidate the exact nature of the previously unknown AFM ground state of KMn 6 Bi 5 and report finding transverse incommensurate spin density waves (SDWs) for the Mn atoms with a propagating direction along the chains. The SDWs have distinct refined amplitudes of ~2.46μ B for the Mn atoms in the pentagons and ~0.29μ B with a large standard deviation for Mn atoms at the center between the pentagons. AFM coupling dominates both the nearest-neighbor Mn-Mn interactions within the pentagon and next-nearest-neighbor Mn-Mn interactions out of the pentagon (along the propagating wave). The SDWs exhibit both local and itinerant characteristics potentially due to cooperative interactions between local magnetic exchange and conduction electrons. Single crystal x-ray diffraction below the AFM transition revealed satellite peaks originating from charge density waves along the chain direction with a q vector twice as large as that of the SDW, pointing to a strong real space coupling between them. Additionally, we report a significant magnetoelastic effect during the AFM transition, especially along the chain direction, observed in temperature-dependent x-ray powder diffraction. Our work not only reveals fascinating intertwined spin, charge, and lattice orders in one-dimensional KMn 6 Bi 5 , but also provides an essential piece of information on its magnetic structure to understand the mechanism of superconductivity in this Mn-based family.

1-dimensional systems↗
DOE OSTI2020

Materials Data on Cs3BiO3 by Materials Project

Cs3BiO3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (3.14 Å) and three longer (3.31 Å) Cs–O bond lengths. In the second Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (3.16 Å) and three longer (3.27 Å) Cs–O bond lengths. In the third Cs1+ site, Cs1+ is bonded in a distorted T-shaped geometry to three equivalent O2- atoms. All Cs–O bond lengths are 2.86 Å. Bi3+ is bonded in a distorted trigonal non-coplanar geometry to three equivalent O2- atoms. All Bi–O bond lengths are 2.10 Å. O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Bi3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsBi4Se7 by Materials Project

CsBi4Se7 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Cs1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.64–3.92 Å. There are four inequivalent Bi+3.25+ sites. In the first Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 5–6°. There are a spread of Bi–Se bond distances ranging from 2.92–3.01 Å. In the second Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Bi–Se bond distances ranging from 2.77–3.16 Å. In the third Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are a spread of Bi–Se bond distances ranging from 2.80–3.17 Å. In the fourth Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Bi–Se bond distances ranging from 2.75–3.32 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Bi+3.25+ and one Se2- atom. The Se–Se bond length is 2.37 Å. In the second Se2- site, Se2- is bonded to two equivalent Cs1+ and three Bi+3.25+ atoms to form distorted SeCs2Bi3 square pyramids that share a cornercorner with one SeBi6 octahedra, corners with six SeCs2Bi3 trigonal bipyramids, edges with two equivalent SeBi6 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two SeCs2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°. In the third Se2- site, Se2- is bonded in a distorted T-shaped geometry to three Bi+3.25+ atoms. In the fourth Se2- site, Se2- is bonded to six Bi+3.25+ atoms to form SeBi6 octahedra that share a cornercorner with one SeCs2Bi3 square pyramid, edges with four equivalent SeBi6 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two equivalent SeCsBi4 trigonal bipyramids. In the fifth Se2- site, Se2- is bonded in a distorted see-saw-like geometry to one Cs1+ and three Bi+3.25+ atoms. In the sixth Se2- site, Se2- is bonded to two equivalent Cs1+ and three equivalent Bi+3.25+ atoms to form distorted SeCs2Bi3 trigonal bipyramids that share corners with two equivalent SeCs2Bi3 square pyramids, a cornercorner with one SeCsBi4 trigonal bipyramid, an edgeedge with one SeCs2Bi3 square pyramid, and edges with six SeCs2Bi3 trigonal bipyramids. In the seventh Se2- site, Se2- is bonded to one Cs1+ and four Bi+3.25+ atoms to form distorted SeCsBi4 trigonal bipyramids that share corners with four equivalent SeCs2Bi3 square pyramids, corners with three SeCs2Bi3 trigonal bipyramids, edges with two equivalent SeBi6 octahedra, an edgeedge with one SeCs2Bi3 square pyramid, and edges with two equivalent SeCs2Bi3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Bi2I9 by Materials Project

Cs3Bi2I9 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve I1- atoms to form CsI12 cuboctahedra that share corners with nine CsI12 cuboctahedra, corners with three equivalent BiI6 octahedra, faces with seven CsI12 cuboctahedra, and faces with four equivalent BiI6 octahedra. The corner-sharing octahedral tilt angles are 17°. There are a spread of Cs–I bond distances ranging from 4.32–4.49 Å. In the second Cs1+ site, Cs1+ is bonded to twelve I1- atoms to form CsI12 cuboctahedra that share corners with twelve CsI12 cuboctahedra, faces with six equivalent CsI12 cuboctahedra, and faces with six equivalent BiI6 octahedra. There are six shorter (4.32 Å) and six longer (4.44 Å) Cs–I bond lengths. Bi3+ is bonded to six I1- atoms to form BiI6 octahedra that share corners with three equivalent CsI12 cuboctahedra, faces with seven CsI12 cuboctahedra, and a faceface with one BiI6 octahedra. There are three shorter (2.98 Å) and three longer (3.25 Å) Bi–I bond lengths. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted single-bond geometry to four Cs1+ and one Bi3+ atom. In the second I1- site, I1- is bonded in a 6-coordinate geometry to four Cs1+ and two equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Bi11Se18 by Materials Project

Cs3Bi11Se18 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.72–4.28 Å. In the second Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.72–4.25 Å. There are seven inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are a spread of Bi–Se bond distances ranging from 2.80–3.13 Å. In the second Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Bi–Se bond distances ranging from 2.85–3.07 Å. In the third Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of distorted corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 6–19°. There are a spread of Bi–Se bond distances ranging from 2.73–3.32 Å. In the fourth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of Bi–Se bond distances ranging from 2.87–3.15 Å. In the fifth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. There are a spread of Bi–Se bond distances ranging from 2.82–3.20 Å. In the sixth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Bi–Se bond distances ranging from 2.88–3.12 Å. In the seventh Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of distorted corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 4–19°. There are a spread of Bi–Se bond distances ranging from 2.70–3.45 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to one Cs1+ and three Bi3+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to one Cs1+ and four Bi3+ atoms. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to two Cs1+ and two Bi3+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Bi3+ atoms. In the fifth Se2- site, Se2- is bonded to two equivalent Cs1+ and three Bi3+ atoms to form distorted edge-sharing SeCs2Bi3 square pyramids. In the sixth Se2- site, Se2- is bonded to two Cs1+ and four Bi3+ atoms to form distorted SeCs2Bi4 octahedra that share edges with three SeCs2Bi4 octahedra and an edgeedge with one SeCs2Bi3 square pyramid. In the seventh Se2- site, Se2- is bonded to six Bi3+ atoms to form edge-sharing SeBi6 octahedra. In the eighth Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share edges with five SeCs2Bi4 octahedra and an edgeedge with one SeCs2Bi3 square pyramid. In the ninth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Cs1+ and two Bi3+ atoms. In the tenth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Cs1+ and two equivalent Bi3+ atoms. In the eleventh Se2- site, Se2- is bonded in a 5-coordinate geometry to one Cs1+ and four Bi3+ atoms. In the twelfth Se2- site, Se2- is bonded in a 6-coordinate geometry to one Cs1+ and five Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsBiS2 by Materials Project

CsBiS2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Cs1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Cs–S bond distances ranging from 3.60–3.99 Å. Bi3+ is bonded in a distorted rectangular see-saw-like geometry to five S2- atoms. There are a spread of Bi–S bond distances ranging from 2.57–3.57 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to four equivalent Cs1+ and two equivalent Bi3+ atoms to form a mixture of distorted edge, face, and corner-sharing SCs4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 39–41°. In the second S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent Cs1+ and three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗