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DOE OSTI2020

Materials Data on Cr4In2(CuSe4)3 by Materials Project

Cr4In2(CuSe4)3 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two InSe6 octahedra, and edges with four equivalent CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.53–2.58 Å. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two equivalent CrSe6 octahedra, and edges with four InSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.52–2.56 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two InSe6 octahedra, and edges with four CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.54–2.58 Å. There are three inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three equivalent InSe6 octahedra and corners with nine CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are three shorter (2.43 Å) and one longer (2.50 Å) Cu–Se bond lengths. In the second Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with five InSe6 octahedra and corners with seven CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–65°. There are a spread of Cu–Se bond distances ranging from 2.40–2.49 Å. In the third Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four InSe6 octahedra and corners with eight CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 53–64°. There are three shorter (2.43 Å) and one longer (2.46 Å) Cu–Se bond lengths. There are three inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with six CuSe4 tetrahedra, an edgeedge with one InSe6 octahedra, and edges with five CrSe6 octahedra. There are a spread of In–Se bond distances ranging from 2.71–2.75 Å. In the second In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with six equivalent CuSe4 tetrahedra and edges with six CrSe6 octahedra. There are four shorter (2.74 Å) and two longer (2.75 Å) In–Se bond lengths. In the third In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two equivalent InSe6 octahedra, and edges with four equivalent CrSe6 octahedra. There are four shorter (2.72 Å) and two longer (2.75 Å) In–Se bond lengths. There are nine inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cr3+ and one Cu2+ atom. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two equivalent Cr3+, one Cu2+, and one In3+ atom. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cr3+ and one Cu2+ atom. In the fourth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two equivalent Cr3+, one Cu2+, and one In3+ atom. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two equivalent Cr3+, one Cu2+, and one In3+ atom. In the sixth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two equivalent Cr3+, one Cu2+, and one In3+ atom. In the seventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two Cr3+, one Cu2+, and one In3+ atom. In the eighth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cr3+, one Cu2+, and two In3+ atoms. In the ninth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to two Cr3+, one Cu2+, and one In3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd2Fe3Cu10(SnSe4)5 by Materials Project

Fe3Cu10Cd2(SnSe4)5 is Clathrate-derived structured and crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share corners with four SnSe4 tetrahedra and corners with eight CuSe4 tetrahedra. All Fe–Se bond lengths are 2.43 Å. In the second Fe3+ site, Fe3+ is bonded to four Se2- atoms to form FeSe4 tetrahedra that share corners with four SnSe4 tetrahedra and corners with eight equivalent CuSe4 tetrahedra. There are two shorter (2.43 Å) and two longer (2.44 Å) Fe–Se bond lengths. There are three inequivalent Cu+1.10+ sites. In the first Cu+1.10+ site, Cu+1.10+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four FeSe4 tetrahedra, corners with four CuSe4 tetrahedra, and corners with four SnSe4 tetrahedra. All Cu–Se bond lengths are 2.45 Å. In the second Cu+1.10+ site, Cu+1.10+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent FeSe4 tetrahedra, corners with two equivalent CdSe4 tetrahedra, corners with four CuSe4 tetrahedra, and corners with four SnSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.42–2.45 Å. In the third Cu+1.10+ site, Cu+1.10+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four CuSe4 tetrahedra, corners with four equivalent CdSe4 tetrahedra, and corners with four equivalent SnSe4 tetrahedra. There are two shorter (2.41 Å) and two longer (2.42 Å) Cu–Se bond lengths. Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with four SnSe4 tetrahedra and corners with eight CuSe4 tetrahedra. All Cd–Se bond lengths are 2.67 Å. There are three inequivalent Sn+3.20+ sites. In the first Sn+3.20+ site, Sn+3.20+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with four FeSe4 tetrahedra and corners with eight equivalent CuSe4 tetrahedra. All Sn–Se bond lengths are 2.68 Å. In the second Sn+3.20+ site, Sn+3.20+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share a cornercorner with one CdSe4 tetrahedra, corners with three FeSe4 tetrahedra, and corners with eight CuSe4 tetrahedra. There are one shorter (2.63 Å) and three longer (2.65 Å) Sn–Se bond lengths. In the third Sn+3.20+ site, Sn+3.20+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share a cornercorner with one FeSe4 tetrahedra, corners with three equivalent CdSe4 tetrahedra, and corners with eight CuSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.61–2.64 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Fe3+, two Cu+1.10+, and one Sn+3.20+ atom to form corner-sharing SeFeCu2Sn tetrahedra. In the second Se2- site, Se2- is bonded to one Fe3+, two equivalent Cu+1.10+, and one Sn+3.20+ atom to form corner-sharing SeFeCu2Sn tetrahedra. In the third Se2- site, Se2- is bonded to one Fe3+, two equivalent Cu+1.10+, and one Sn+3.20+ atom to form corner-sharing SeFeCu2Sn tetrahedra. In the fourth Se2- site, Se2- is bonded to two equivalent Cu+1.10+, one Cd2+, and one Sn+3.20+ atom to form corner-sharing SeCdCu2Sn tetrahedra. In the fifth Se2- site, Se2- is bonded to two equivalent Cu+1.10+, one Cd2+, and one Sn+3.20+ atom to form corner-sharing SeCdCu2Sn tetrahedra. In the sixth Se2- site, Se2- is bonded to one Fe3+, two equivalent Cu+1.10+, and one Sn+3.20+ atom to form corner-sharing SeFeCu2Sn tetrahedra. In the seventh Se2- site, Se2- is bonded to one Fe3+, two equivalent Cu+1.10+, and one Sn+3.20+ atom to form corner-sharing SeFeCu2Sn tetrahedra. In the eighth Se2- site, Se2- is bonded to two Cu+1.10+, one Cd2+, and one Sn+3.20+ atom to form corner-sharing SeCdCu2Sn tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KBa3Ga5(Se5Cl)2 by Materials Project

KBa3Ga5(Se5Cl)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. K1+ is bonded in a 2-coordinate geometry to seven Se2- and two Cl1- atoms. There are a spread of K–Se bond distances ranging from 3.40–3.87 Å. There are one shorter (3.16 Å) and one longer (3.26 Å) K–Cl bond lengths. There are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to eight Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.39–4.01 Å. There are one shorter (3.14 Å) and one longer (3.21 Å) Ba–Cl bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to seven Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.38–3.87 Å. There are one shorter (3.13 Å) and one longer (3.21 Å) Ba–Cl bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to eight Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.34–4.02 Å. There are one shorter (3.14 Å) and one longer (3.19 Å) Ba–Cl bond lengths. There are five inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.44 Å. In the second Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.41–2.45 Å. In the third Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are two shorter (2.42 Å) and two longer (2.44 Å) Ga–Se bond lengths. In the fourth Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.44 Å. In the fifth Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.43–2.46 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to three Ba2+ and two Ga3+ atoms. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the fifth Se2- site, Se2- is bonded in a distorted water-like geometry to three Ba2+ and two Ga3+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted water-like geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the eighth Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the ninth Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, two Ba2+, and two Ga3+ atoms. In the tenth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Ba2+ and two Ga3+ atoms. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to one K1+ and three Ba2+ atoms to form corner-sharing ClKBa3 tetrahedra. In the second Cl1- site, Cl1- is bonded to one K1+ and three Ba2+ atoms to form distorted corner-sharing ClKBa3 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdMgSe3 by Materials Project

MgNdSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded to six Se+1.67- atoms to form MgSe6 octahedra that share corners with eight equivalent NdSe4 tetrahedra and edges with three equivalent MgSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.67–3.03 Å. Nd3+ is bonded to four Se+1.67- atoms to form NdSe4 tetrahedra that share corners with eight equivalent MgSe6 octahedra and an edgeedge with one NdSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–76°. There are a spread of Nd–Se bond distances ranging from 2.81–2.83 Å. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one Nd3+ atom. In the second Se+1.67- site, Se+1.67- is bonded to two equivalent Mg2+ and two equivalent Nd3+ atoms to form edge-sharing SeNd2Mg2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaMgSe3 by Materials Project

MgLaSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded to six Se+1.67- atoms to form distorted MgSe6 octahedra that share corners with eight equivalent LaSe4 tetrahedra and edges with three equivalent MgSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.64–3.16 Å. La3+ is bonded to four Se+1.67- atoms to form distorted LaSe4 tetrahedra that share corners with eight equivalent MgSe6 octahedra and an edgeedge with one LaSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–77°. There are a spread of La–Se bond distances ranging from 2.86–2.89 Å. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a 3-coordinate geometry to two equivalent Mg2+ and one La3+ atom. In the second Se+1.67- site, Se+1.67- is bonded to two equivalent Mg2+ and two equivalent La3+ atoms to form edge-sharing SeLa2Mg2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsBa3Ga5(Se5Cl)2 by Materials Project

CsBa3Ga5(Se5Cl)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Cs1+ is bonded in a 10-coordinate geometry to eight Se2- and two Cl1- atoms. There are a spread of Cs–Se bond distances ranging from 3.60–4.14 Å. There are one shorter (3.39 Å) and one longer (3.49 Å) Cs–Cl bond lengths. There are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to eight Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.37–3.98 Å. There are one shorter (3.13 Å) and one longer (3.23 Å) Ba–Cl bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to six Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.30–3.83 Å. There are one shorter (3.14 Å) and one longer (3.15 Å) Ba–Cl bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 2-coordinate geometry to six Se2- and two Cl1- atoms. There are a spread of Ba–Se bond distances ranging from 3.38–3.90 Å. There are one shorter (3.12 Å) and one longer (3.18 Å) Ba–Cl bond lengths. There are five inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.45 Å. In the second Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.41–2.44 Å. In the third Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.46 Å. In the fourth Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.45 Å. In the fifth Ga3+ site, Ga3+ is bonded to four Se2- atoms to form corner-sharing GaSe4 tetrahedra. There are a spread of Ga–Se bond distances ranging from 2.42–2.46 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted water-like geometry to two Ba2+ and two Ga3+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to one Cs1+, one Ba2+, and two Ga3+ atoms. In the third Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, two Ba2+, and two Ga3+ atoms. In the fourth Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, two Ba2+, and two Ga3+ atoms. In the fifth Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, one Ba2+, and two Ga3+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, three Ba2+, and two Ga3+ atoms. In the seventh Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, two Ba2+, and two Ga3+ atoms. In the eighth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Ba2+ and two Ga3+ atoms. In the ninth Se2- site, Se2- is bonded in a 2-coordinate geometry to one Cs1+, two Ba2+, and two Ga3+ atoms. In the tenth Se2- site, Se2- is bonded in a 2-coordinate geometry to one Cs1+, two Ba2+, and two Ga3+ atoms. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a tetrahedral geometry to one Cs1+ and three Ba2+ atoms. In the second Cl1- site, Cl1- is bonded in a 4-coordinate geometry to one Cs1+ and three Ba2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThUSe2 by Materials Project

UThSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. U is bonded to six Se atoms to form USe6 octahedra that share corners with six equivalent USe6 octahedra, edges with four equivalent USe6 octahedra, and edges with eight equivalent ThSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. All U–Se bond lengths are 2.93 Å. Th is bonded to six Se atoms to form ThSe6 octahedra that share corners with six equivalent ThSe6 octahedra, edges with four equivalent ThSe6 octahedra, and edges with eight equivalent USe6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Th–Se bond lengths are 2.93 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded to two equivalent U and four equivalent Th atoms to form a mixture of corner and edge-sharing SeTh4U2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se site, Se is bonded to four equivalent U and two equivalent Th atoms to form SeTh2U4 octahedra that share corners with six equivalent SeTh2U4 octahedra and edges with twelve SeTh4U2 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2V3(SeO)6 by Materials Project

(NaO3)2(VSe2)3 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one NaO3 sheet oriented in the (0, 0, 1) direction and one VSe2 sheet oriented in the (0, 0, 1) direction. In the NaO3 sheet, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four equivalent O2- atoms. There are two shorter (2.24 Å) and two longer (2.26 Å) Na–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one O2- atom. The O–O bond length is 1.35 Å. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent O2- atoms. In the VSe2 sheet, there are two inequivalent V+4.67+ sites. In the first V+4.67+ site, V+4.67+ is bonded to six Se+0.67- atoms to form edge-sharing VSe6 octahedra. There are two shorter (2.55 Å) and four longer (2.58 Å) V–Se bond lengths. In the second V+4.67+ site, V+4.67+ is bonded to six Se+0.67- atoms to form edge-sharing VSe6 octahedra. There are four shorter (2.58 Å) and two longer (2.60 Å) V–Se bond lengths. There are two inequivalent Se+0.67- sites. In the first Se+0.67- site, Se+0.67- is bonded in a 3-coordinate geometry to three V+4.67+ atoms. In the second Se+0.67- site, Se+0.67- is bonded in a 4-coordinate geometry to three V+4.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnZn3(CrSe2)8 by Materials Project

MnZn3(CrSe2)8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with three equivalent MnSe4 tetrahedra, corners with three equivalent ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are three shorter (2.55 Å) and three longer (2.56 Å) Cr–Se bond lengths. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six equivalent ZnSe4 tetrahedra and edges with six CrSe6 octahedra. All Cr–Se bond lengths are 2.55 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent MnSe4 tetrahedra, corners with four ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are three shorter (2.55 Å) and three longer (2.56 Å) Cr–Se bond lengths. In the fourth Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share a cornercorner with one MnSe4 tetrahedra, corners with five ZnSe4 tetrahedra, and edges with six CrSe6 octahedra. There are three shorter (2.55 Å) and three longer (2.56 Å) Cr–Se bond lengths. Mn2+ is bonded to four Se2- atoms to form MnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are one shorter (2.48 Å) and three longer (2.49 Å) Mn–Se bond lengths. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four Se2- atoms to form ZnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–Se bond lengths are 2.49 Å. In the second Zn2+ site, Zn2+ is bonded to four Se2- atoms to form ZnSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–Se bond lengths are 2.49 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Cr3+ and one Mn2+ atom to form a mixture of distorted corner and edge-sharing SeMnCr3 trigonal pyramids. In the second Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeZnCr3 trigonal pyramids and edges with three equivalent SeMnCr3 trigonal pyramids. In the third Se2- site, Se2- is bonded to three Cr3+ and one Mn2+ atom to form distorted SeMnCr3 trigonal pyramids that share corners with twelve SeMnCr3 trigonal pyramids and edges with three SeZnCr3 trigonal pyramids. In the fourth Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeZnCr3 trigonal pyramids and edges with three SeMnCr3 trigonal pyramids. In the fifth Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeMnCr3 trigonal pyramids and edges with three equivalent SeZnCr3 trigonal pyramids. In the sixth Se2- site, Se2- is bonded to three equivalent Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeMnCr3 trigonal pyramids and edges with three equivalent SeZnCr3 trigonal pyramids. The Se–Zn bond length is 2.49 Å. In the seventh Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form distorted SeZnCr3 trigonal pyramids that share corners with twelve SeMnCr3 trigonal pyramids and edges with three SeZnCr3 trigonal pyramids. In the eighth Se2- site, Se2- is bonded to three Cr3+ and one Zn2+ atom to form a mixture of distorted corner and edge-sharing SeZnCr3 trigonal pyramids. The Se–Zn bond length is 2.49 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2USe3 by Materials Project

UY2Se3 is Caswellsilverite-like structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. U is bonded to six equivalent Se atoms to form USe6 octahedra that share corners with six equivalent YSe6 octahedra, edges with six equivalent USe6 octahedra, and edges with six equivalent YSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. All U–Se bond lengths are 2.89 Å. Y is bonded to six Se atoms to form YSe6 octahedra that share corners with three equivalent USe6 octahedra, corners with three equivalent YSe6 octahedra, edges with three equivalent USe6 octahedra, and edges with nine equivalent YSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (2.83 Å) and three longer (2.92 Å) Y–Se bond lengths. There are two inequivalent Se sites. In the first Se site, Se is bonded to three equivalent U and three equivalent Y atoms to form a mixture of edge and corner-sharing SeY3U3 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second Se site, Se is bonded to six equivalent Y atoms to form a mixture of edge and corner-sharing SeY6 octahedra. The corner-sharing octahedral tilt angles are 2°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmMgSe3 by Materials Project

MgTmSe3 is Ilmenite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded in a 6-coordinate geometry to six Se+1.67- atoms. There are a spread of Mg–Se bond distances ranging from 2.63–3.33 Å. Tm3+ is bonded to six Se+1.67- atoms to form a mixture of distorted edge and face-sharing TmSe6 pentagonal pyramids. There are a spread of Tm–Se bond distances ranging from 2.71–3.06 Å. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a 2-coordinate geometry to two equivalent Mg2+ and two equivalent Tm3+ atoms. In the second Se+1.67- site, Se+1.67- is bonded to two equivalent Mg2+ and two equivalent Tm3+ atoms to form edge-sharing SeTm2Mg2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4Ge(PSe3)4 by Materials Project

K4Ge(PSe3)4 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.42–3.99 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.48–3.85 Å. In the third K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.35–4.05 Å. In the fourth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.34–3.93 Å. Ge2+ is bonded in a tetrahedral geometry to four Se2- atoms. There are a spread of Ge–Se bond distances ranging from 2.40–2.42 Å. There are four inequivalent P+4.50+ sites. In the first P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.15–2.36 Å. In the second P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.14–2.33 Å. In the third P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.17 Å) and one longer (2.34 Å) P–Se bond lengths. In the fourth P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.14–2.36 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to three K1+ and one P+4.50+ atom. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three K1+ and one P+4.50+ atom. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Ge2+, and one P+4.50+ atom. In the fourth Se2- site, Se2- is bonded in a 1-coordinate geometry to three K1+ and one P+4.50+ atom. In the fifth Se2- site, Se2- is bonded in a 1-coordinate geometry to three K1+ and one P+4.50+ atom. In the sixth Se2- site, Se2- is bonded in a distorted L-shaped geometry to one K1+, one Ge2+, and one P+4.50+ atom. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to two K1+, one Ge2+, and one P+4.50+ atom. In the eighth Se2- site, Se2- is bonded in a 4-coordinate geometry to four K1+ and one P+4.50+ atom. In the ninth Se2- site, Se2- is bonded in a 1-coordinate geometry to three K1+ and one P+4.50+ atom. In the tenth Se2- site, Se2- is bonded in a 2-coordinate geometry to two K1+, one Ge2+, and one P+4.50+ atom. In the eleventh Se2- site, Se2- is bonded in a 1-coordinate geometry to two K1+ and one P+4.50+ atom. In the twelfth Se2- site, Se2- is bonded in a 1-coordinate geometry to three K1+ and one P+4.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaPr2Se3 by Materials Project

NaPr2Se3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Na is bonded to six Se atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with four equivalent PrSe6 octahedra, edges with two equivalent NaSe6 octahedra, and edges with ten equivalent PrSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Na–Se bond lengths are 3.02 Å. Pr is bonded to six Se atoms to form PrSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with four equivalent PrSe6 octahedra, edges with five equivalent NaSe6 octahedra, and edges with seven equivalent PrSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Pr–Se bond distances ranging from 3.00–3.05 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded to two equivalent Na and four equivalent Pr atoms to form a mixture of edge and corner-sharing SeNa2Pr4 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second Se site, Se is bonded to two equivalent Na and four equivalent Pr atoms to form a mixture of edge and corner-sharing SeNa2Pr4 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeNiSe4 by Materials Project

FeNiSe4 is pyrite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Fe3+ is bonded to six Se+1.75- atoms to form FeSe6 octahedra that share corners with four equivalent FeSe6 octahedra and corners with eight equivalent NiSe6 octahedra. The corner-sharing octahedra tilt angles range from 61–64°. There are a spread of Fe–Se bond distances ranging from 2.37–2.41 Å. Ni4+ is bonded to six Se+1.75- atoms to form NiSe6 octahedra that share corners with four equivalent NiSe6 octahedra and corners with eight equivalent FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 62–65°. There are four shorter (2.46 Å) and two longer (2.49 Å) Ni–Se bond lengths. There are two inequivalent Se+1.75- sites. In the first Se+1.75- site, Se+1.75- is bonded in a 3-coordinate geometry to one Fe3+ and two equivalent Ni4+ atoms. In the second Se+1.75- site, Se+1.75- is bonded in a distorted trigonal planar geometry to two equivalent Fe3+ and one Ni4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe2Cu3(Sn3Se8)2 by Materials Project

Fe2Cu3(Sn3Se8)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with four CuSe4 tetrahedra and edges with six SnSe6 octahedra. There are a spread of Fe–Se bond distances ranging from 2.41–2.52 Å. In the second Fe3+ site, Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with five CuSe4 tetrahedra and edges with six SnSe6 octahedra. There are a spread of Fe–Se bond distances ranging from 2.40–2.48 Å. There are three inequivalent Cu+1.33+ sites. In the first Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Cu–Se bond distances ranging from 2.41–2.50 Å. In the second Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Cu–Se bond distances ranging from 2.41–2.51 Å. In the third Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–61°. There are a spread of Cu–Se bond distances ranging from 2.40–2.49 Å. There are four inequivalent Sn+3.67+ sites. In the first Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with five CuSe4 tetrahedra, edges with two equivalent FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.72–2.78 Å. In the second Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with four CuSe4 tetrahedra, edges with two equivalent FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.72–2.76 Å. In the third Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with four CuSe4 tetrahedra, edges with two FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.70–2.78 Å. In the fourth Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with five CuSe4 tetrahedra, edges with two FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.71–2.75 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to three Sn+3.67+ atoms. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to one Fe3+ and two equivalent Sn+3.67+ atoms. In the fourth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Fe3+ and two Sn+3.67+ atoms. In the seventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the eighth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the ninth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the tenth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the eleventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms. In the twelfth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na9Sm(GeSe3)4 by Materials Project

Na9Sm(Ge2Se6)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are six inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share a cornercorner with one SmSe6 octahedra, corners with three NaSe6 octahedra, an edgeedge with one SmSe6 octahedra, and edges with nine NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Na–Se bond distances ranging from 3.03–3.26 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share a cornercorner with one SmSe6 octahedra, corners with three NaSe6 octahedra, an edgeedge with one SmSe6 octahedra, and edges with nine NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–13°. There are a spread of Na–Se bond distances ranging from 3.01–3.29 Å. In the third Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share a cornercorner with one SmSe6 octahedra, corners with three NaSe6 octahedra, an edgeedge with one SmSe6 octahedra, and edges with nine NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Na–Se bond distances ranging from 2.95–3.18 Å. In the fourth Na1+ site, Na1+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. There are two shorter (3.07 Å) and four longer (3.10 Å) Na–Se bond lengths. In the fifth Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with six NaSe6 octahedra, an edgeedge with one SmSe6 octahedra, and edges with eight NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Na–Se bond distances ranging from 3.06–3.14 Å. In the sixth Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with six NaSe6 octahedra, edges with two equivalent SmSe6 octahedra, and edges with seven NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. There are a spread of Na–Se bond distances ranging from 3.04–3.11 Å. Sm3+ is bonded to six Se2- atoms to form SmSe6 octahedra that share corners with six NaSe6 octahedra and edges with nine NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–7°. There are a spread of Sm–Se bond distances ranging from 2.95–2.98 Å. There are two inequivalent Ge3+ sites. In the first Ge3+ site, Ge3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of Ge–Se bond distances ranging from 2.37–2.46 Å. In the second Ge3+ site, Ge3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.36 Å) and two longer (2.41 Å) Ge–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four Na1+, one Sm3+, and one Ge3+ atom to form SeNa4SmGe octahedra that share corners with seven SeNa4SmGe octahedra and edges with ten SeNa5Ge octahedra. The corner-sharing octahedra tilt angles range from 4–87°. In the second Se2- site, Se2- is bonded to five Na1+ and one Ge3+ atom to form a mixture of corner and edge-sharing SeNa5Ge octahedra. The corner-sharing octahedra tilt angles range from 2–86°. In the third Se2- site, Se2- is bonded to five Na1+ and one Ge3+ atom to form SeNa5Ge octahedra that share corners with seven SeNa5Ge octahedra and edges with ten SeNa4SmGe octahedra. The corner-sharing octahedra tilt angles range from 2–85°. In the fourth Se2- site, Se2- is bonded to four Na1+, one Sm3+, and one Ge3+ atom to form a mixture of corner and edge-sharing SeNa4SmGe octahedra. The corner-sharing octahedra tilt angles range from 3–87°. In the fifth Se2- site, Se2- is bonded to five Na1+ and one Ge3+ atom to form a mixture of corner and edge-sharing SeNa5Ge octahedra. The corner-sharing octahedra tilt angles range from 2–87°. In the sixth Se2- site, Se2- is bonded to four Na1+, one Sm3+, and one Ge3+ atom to form a mixture of corner and edge-sharing SeNa4SmGe octahedra. The corner-sharing octahedra tilt angles range from 2–87°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu6BiSe6 by Materials Project

Cu6BiSe6 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are six inequivalent Cu+1.50+ sites. In the first Cu+1.50+ site, Cu+1.50+ is bonded to four Se2- atoms to form a mixture of edge and corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.44–2.55 Å. In the second Cu+1.50+ site, Cu+1.50+ is bonded to four Se2- atoms to form a mixture of distorted edge and corner-sharing CuSe4 trigonal pyramids. There are a spread of Cu–Se bond distances ranging from 2.37–2.49 Å. In the third Cu+1.50+ site, Cu+1.50+ is bonded in a distorted trigonal non-coplanar geometry to four Se2- atoms. There are a spread of Cu–Se bond distances ranging from 2.39–2.90 Å. In the fourth Cu+1.50+ site, Cu+1.50+ is bonded to four Se2- atoms to form a mixture of edge and corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.47–2.50 Å. In the fifth Cu+1.50+ site, Cu+1.50+ is bonded to four Se2- atoms to form a mixture of distorted edge and corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.43–2.69 Å. In the sixth Cu+1.50+ site, Cu+1.50+ is bonded to four Se2- atoms to form corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.42–2.57 Å. Bi3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Bi–Se bond distances ranging from 2.77–3.50 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four Cu+1.50+ and one Se2- atom. The Se–Se bond length is 2.55 Å. In the second Se2- site, Se2- is bonded in a distorted hexagonal planar geometry to six Cu+1.50+ atoms. In the third Se2- site, Se2- is bonded to two Cu+1.50+ and two equivalent Bi3+ atoms to form distorted corner-sharing SeCu2Bi2 tetrahedra. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Cu+1.50+ and two equivalent Bi3+ atoms. In the fifth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Cu+1.50+ and one Bi3+ atom. In the sixth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Cu+1.50+, two equivalent Bi3+, and one Se2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs4Ge(PSe3)4 by Materials Project

Cs4Ge(PSe3)4 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are four inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to ten Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.78–4.40 Å. In the second 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 3.76–4.21 Å. In the third 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 3.60–4.26 Å. In the fourth 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 3.61–4.27 Å. Ge2+ is bonded in a tetrahedral geometry to four Se2- atoms. There are three shorter (2.40 Å) and one longer (2.41 Å) Ge–Se bond lengths. There are four inequivalent P+4.50+ sites. In the first P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.15–2.36 Å. In the second P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.15–2.33 Å. In the third P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.16 Å) and one longer (2.35 Å) P–Se bond lengths. In the fourth P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.14–2.35 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to three Cs1+ and one P+4.50+ atom. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cs1+ and one P+4.50+ atom. In the third Se2- site, Se2- is bonded in a distorted water-like geometry to two equivalent Cs1+, one Ge2+, and one P+4.50+ atom. In the fourth Se2- site, Se2- is bonded in a distorted single-bond geometry to four Cs1+ and one P+4.50+ atom. In the fifth Se2- site, Se2- is bonded in a distorted single-bond geometry to three Cs1+ and one P+4.50+ atom. In the sixth Se2- site, Se2- is bonded in a distorted L-shaped geometry to one Cs1+, one Ge2+, and one P+4.50+ atom. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to two Cs1+, one Ge2+, and one P+4.50+ atom. In the eighth Se2- site, Se2- is bonded in a 1-coordinate geometry to four Cs1+ and one P+4.50+ atom. In the ninth Se2- site, Se2- is bonded in a 1-coordinate geometry to three Cs1+ and one P+4.50+ atom. In the tenth Se2- site, Se2- is bonded in a distorted L-shaped geometry to three Cs1+, one Ge2+, and one P+4.50+ atom. In the eleventh Se2- site, Se2- is bonded in a distorted single-bond geometry to four Cs1+ and one P+4.50+ atom. In the twelfth Se2- site, Se2- is bonded in a distorted single-bond geometry to three Cs1+ and one P+4.50+ atom.

36 MATERIALS SCIENCE↗