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Materials Data on YSe2 by Materials Project

YSe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Y3+ is bonded in a 9-coordinate geometry to nine Se+1.50- atoms. There are a spread of Y–Se bond distances ranging from 2.98–3.07 Å. There are two inequivalent Se+1.50- sites. In the first Se+1.50- site, Se+1.50- is bonded in a 8-coordinate geometry to four equivalent Y3+ and four equivalent Se+1.50- atoms. All Se–Se bond lengths are 2.88 Å. In the second Se+1.50- site, Se+1.50- is bonded to five equivalent Y3+ atoms to form a mixture of distorted corner and edge-sharing SeY5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Bi8Se13 by Materials Project

K2Bi8Se13 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of K–Se bond distances ranging from 3.30–3.96 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 3.20–3.88 Å. There are eight inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to five Se2- atoms to form distorted BiSe5 square pyramids that share corners with four BiSe6 octahedra, an edgeedge with one BiSe6 octahedra, and edges with two equivalent BiSe5 square pyramids. The corner-sharing octahedra tilt angles range from 11–89°. There are a spread of Bi–Se bond distances ranging from 2.62–3.37 Å. In the second Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–65°. There are a spread of Bi–Se bond distances ranging from 2.93–3.04 Å. In the third Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Bi–Se bond distances ranging from 2.87–3.12 Å. In the fourth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form BiSe6 octahedra that share corners with three BiSe6 octahedra, corners with two equivalent BiSe5 square pyramids, edges with nine BiSe6 octahedra, and an edgeedge with one BiSe5 square pyramid. The corner-sharing octahedra tilt angles range from 1–2°. There are a spread of Bi–Se bond distances ranging from 2.83–3.24 Å. In the fifth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Bi–Se bond distances ranging from 2.85–3.24 Å. In the sixth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Bi–Se bond distances ranging from 2.85–3.14 Å. In the seventh Bi3+ site, Bi3+ is bonded to six Se2- atoms to form BiSe6 octahedra that share corners with two equivalent BiSe6 octahedra, corners with two equivalent BiSe5 square pyramids, and edges with seven BiSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Bi–Se bond distances ranging from 2.79–3.31 Å. In the eighth Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Bi–Se bond distances ranging from 2.87–3.50 Å. There are thirteen inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four K1+ and one Bi3+ atom to form distorted SeK4Bi square pyramids that share corners with two equivalent SeK2Bi3 square pyramids, corners with two equivalent SeK2Bi3 trigonal bipyramids, edges with two equivalent SeKBi5 octahedra, edges with three SeK4Bi square pyramids, and an edgeedge with one SeK2Bi3 trigonal bipyramid. In the second Se2- site, Se2- is bonded to two equivalent K1+ and three Bi3+ atoms to form distorted SeK2Bi3 square pyramids that share a cornercorner with one SeBi6 octahedra, corners with two equivalent SeK4Bi square pyramids, corners with two equivalent SeK2Bi3 trigonal bipyramids, edges with four SeKBi5 octahedra, edges with three SeK4Bi square pyramids, and an edgeedge with one SeK2Bi3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 4°. In the third Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share corners with two equivalent SeKBi5 octahedra, a cornercorner with one SeK2Bi3 square pyramid, edges with seven SeKBi5 octahedra, and edges with two equivalent SeK2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the fourth Se2- site, Se2- is bonded to two equivalent K1+ and three Bi3+ atoms to form distorted SeK2Bi3 trigonal bipyramids that share corners with four SeBi6 octahedra, corners with four SeK4Bi square pyramids, an edgeedge with one SeBi6 octahedra, edges with two SeK4Bi square pyramids, and edges with two equivalent SeK2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 3–44°. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Bi3+ atoms. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to two K1+ and three Bi3+ atoms. In the seventh Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent K1+ and two equivalent Bi3+ atoms. In the eighth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to four Bi3+ atoms. In the ninth Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent K1+ and three Bi3+ atoms. In the tenth Se2- site, Se2- is bonded in a 4-coordinate geometry to one K1+ and three Bi3+ atoms. In the eleventh Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share corners with two equivalent SeK2Bi3 trigonal bipyramids, edges with four equivalent SeBi6 octahedra, and an edgeedge with one SeK2Bi3 trigonal bipyramid. In the twelfth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Bi3+ atoms. In the thirteenth Se2- site, Se2- is bonded to one K1+ and five Bi3+ atoms to form SeKBi5 octahedra that share corners with two equivalent SeBi6 octahedra, corners with two equivalent SeK2Bi3 trigonal bipyramids, edges with five SeKBi5 octahedra, and edges with four SeK4Bi square pyramids. The corner-sharing octahedral tilt angles are 5°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Y7Se12 by Materials Project

Cs3Y7Se12 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.68–3.83 Å. In the second Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.54–3.82 Å. In the third 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 3.53–4.04 Å. There are seven inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six Se2- atoms to form edge-sharing YSe6 octahedra. There are a spread of Y–Se bond distances ranging from 2.80–3.02 Å. In the second Y3+ site, Y3+ is bonded to six Se2- atoms to form edge-sharing YSe6 octahedra. There are a spread of Y–Se bond distances ranging from 2.83–2.98 Å. In the third Y3+ site, Y3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing YSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Y–Se bond distances ranging from 2.82–2.99 Å. In the fourth Y3+ site, Y3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing YSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Y–Se bond distances ranging from 2.81–2.99 Å. In the fifth Y3+ site, Y3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are a spread of Y–Se bond distances ranging from 2.86–2.92 Å. In the sixth Y3+ site, Y3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Y–Se bond distances ranging from 2.81–3.02 Å. In the seventh Y3+ site, Y3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing YSe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Y–Se bond distances ranging from 2.82–3.04 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Cs1+ and four Y3+ atoms to form distorted SeCsY4 trigonal bipyramids that share corners with two equivalent SeCs2Y3 square pyramids, corners with three SeCs2Y3 trigonal bipyramids, and edges with three SeY5 square pyramids. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Cs1+ and four Y3+ atoms. In the third Se2- site, Se2- is bonded to five Y3+ atoms to form SeY5 square pyramids that share corners with two equivalent SeCs2Y3 trigonal bipyramids, edges with four SeY5 square pyramids, and edges with two equivalent SeCsY4 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded to five Y3+ atoms to form SeY5 square pyramids that share corners with two equivalent SeCs2Y3 trigonal bipyramids, edges with two equivalent SeY5 square pyramids, and an edgeedge with one SeCs2Y3 trigonal bipyramid. In the fifth Se2- site, Se2- is bonded to two equivalent Cs1+ and three Y3+ atoms to form distorted SeCs2Y3 square pyramids that share corners with two equivalent SeCsY4 trigonal bipyramids, edges with four SeY5 square pyramids, and an edgeedge with one SeCsY4 trigonal bipyramid. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Y3+ atoms. In the seventh Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Y3+ atoms. In the eighth Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Y3+ atoms. In the ninth Se2- site, Se2- is bonded to two equivalent Cs1+ and three Y3+ atoms to form distorted SeCs2Y3 trigonal bipyramids that share corners with four SeY5 square pyramids, a cornercorner with one SeCsY4 trigonal bipyramid, an edgeedge with one SeY5 square pyramid, and edges with two equivalent SeCs2Y3 trigonal bipyramids. In the tenth Se2- site, Se2- is bonded in a 6-coordinate geometry to three Cs1+ and three Y3+ atoms. In the eleventh Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Y3+ atoms. In the twelfth Se2- site, Se2- is bonded in a 6-coordinate geometry to three Cs1+ and three Y3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TmSe2 by Materials Project

TmSe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Tm3+ is bonded in a 9-coordinate geometry to nine Se+1.50- atoms. There are a spread of Tm–Se bond distances ranging from 2.92–3.03 Å. There are two inequivalent Se+1.50- sites. In the first Se+1.50- site, Se+1.50- is bonded in a 8-coordinate geometry to four equivalent Tm3+ and four equivalent Se+1.50- atoms. All Se–Se bond lengths are 2.86 Å. In the second Se+1.50- site, Se+1.50- is bonded to five equivalent Tm3+ atoms to form a mixture of distorted edge and corner-sharing SeTm5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmSe2 by Materials Project

PmSe2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Pm3+ is bonded in a 9-coordinate geometry to nine Se+1.50- atoms. There are a spread of Pm–Se bond distances ranging from 2.98–3.22 Å. There are two inequivalent Se+1.50- sites. In the first Se+1.50- site, Se+1.50- is bonded in a 5-coordinate geometry to four equivalent Pm3+ and one Se+1.50- atom. The Se–Se bond length is 2.55 Å. In the second Se+1.50- site, Se+1.50- is bonded to five equivalent Pm3+ atoms to form a mixture of distorted edge and corner-sharing SePm5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na4ZnSe3 by Materials Project

Na4ZnSe3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three Se2- atoms. There are a spread of Na–Se bond distances ranging from 2.87–3.62 Å. In the second Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Na–Se bond distances ranging from 3.05–3.32 Å. In the third Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Na–Se bond distances ranging from 2.33–3.07 Å. In the fourth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to three Se2- atoms. There are a spread of Na–Se bond distances ranging from 2.95–3.62 Å. In the fifth Na1+ site, Na1+ is bonded in a distorted single-bond geometry to two Se2- atoms. There are one shorter (2.02 Å) and one longer (3.18 Å) Na–Se bond lengths. In the sixth Na1+ site, Na1+ is bonded in a distorted water-like geometry to two Se2- atoms. There are one shorter (1.89 Å) and one longer (2.52 Å) Na–Se bond lengths. In the seventh Na1+ site, Na1+ is bonded in a 1-coordinate geometry to one Zn2+ and three Se2- atoms. The Na–Zn bond length is 2.74 Å. There are a spread of Na–Se bond distances ranging from 2.50–3.51 Å. In the eighth Na1+ site, Na1+ is bonded in a 1-coordinate geometry to four Se2- atoms. There are a spread of Na–Se bond distances ranging from 1.88–3.40 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded in a 2-coordinate geometry to one Na1+ and three Se2- atoms. There are a spread of Zn–Se bond distances ranging from 1.79–2.71 Å. In the second Zn2+ site, Zn2+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Zn–Se bond distances ranging from 1.61–2.38 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted linear geometry to six Na1+ and one Zn2+ atom. In the second Se2- site, Se2- is bonded in a distorted linear geometry to two Na1+ and one Zn2+ atom. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to three Na1+ and one Zn2+ atom. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to five Na1+ and one Zn2+ atom. In the fifth Se2- site, Se2- is bonded in a 1-coordinate geometry to four Na1+ and one Zn2+ atom. In the sixth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Na1+ and one Zn2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Se3Br by Materials Project

(Se)2SeBr crystallizes in the tetragonal I4/mmm space group. The structure is two-dimensional and consists of two Se sheets oriented in the (0, 0, 1) direction and two SeBr sheets oriented in the (0, 0, 1) direction. In each Se sheet, Se+1.67- is bonded in a square co-planar geometry to four equivalent Se+1.67- atoms. All Se–Se bond lengths are 2.69 Å. In each SeBr sheet, Se+1.67- is bonded in a square co-planar geometry to four equivalent Br5+ atoms. All Se–Br bond lengths are 2.69 Å. Br5+ is bonded in a square co-planar geometry to four equivalent Se+1.67- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuSe2 by Materials Project

EuSe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Eu3+ is bonded in a 9-coordinate geometry to nine Se+1.50- atoms. There are a spread of Eu–Se bond distances ranging from 2.99–3.27 Å. There are two inequivalent Se+1.50- sites. In the first Se+1.50- site, Se+1.50- is bonded in a 8-coordinate geometry to four equivalent Eu3+ and four equivalent Se+1.50- atoms. All Se–Se bond lengths are 2.90 Å. In the second Se+1.50- site, Se+1.50- is bonded to five equivalent Eu3+ atoms to form a mixture of distorted edge and corner-sharing SeEu5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag6Au2Se3S by Materials Project

Au2Ag6Se3S crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Au1+ sites. In the first Au1+ site, Au1+ is bonded in a 8-coordinate geometry to six Ag1+, one Se2-, and one S2- atom. There are a spread of Au–Ag bond distances ranging from 3.04–3.14 Å. The Au–Se bond length is 2.51 Å. The Au–S bond length is 2.37 Å. In the second Au1+ site, Au1+ is bonded in a 8-coordinate geometry to six Ag1+ and two Se2- atoms. There are a spread of Au–Ag bond distances ranging from 3.07–3.13 Å. There are one shorter (2.50 Å) and one longer (2.51 Å) Au–Se bond lengths. There are eight inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two equivalent Au1+, two equivalent Se2-, and two equivalent S2- atoms. Both Ag–Se bond lengths are 2.77 Å. Both Ag–S bond lengths are 2.89 Å. In the second Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two equivalent Au1+ and four Se2- atoms. There are two shorter (2.76 Å) and two longer (2.90 Å) Ag–Se bond lengths. In the third Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two equivalent Au1+ and four Se2- atoms. There are two shorter (2.77 Å) and two longer (2.90 Å) Ag–Se bond lengths. In the fourth Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to two equivalent Au1+, two equivalent Se2-, and two equivalent S2- atoms. Both Ag–Se bond lengths are 2.93 Å. Both Ag–S bond lengths are 2.73 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two Au1+, three Se2-, and one S2- atom. There are a spread of Ag–Se bond distances ranging from 2.75–2.93 Å. The Ag–S bond length is 2.86 Å. In the sixth Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to two Au1+, three Se2-, and one S2- atom. There are a spread of Ag–Se bond distances ranging from 2.77–2.94 Å. The Ag–S bond length is 2.71 Å. In the seventh Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to two Au1+, three Se2-, and one S2- atom. There are two shorter (2.76 Å) and one longer (2.94 Å) Ag–Se bond lengths. The Ag–S bond length is 2.85 Å. In the eighth Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to two Au1+, three Se2-, and one S2- atom. There are a spread of Ag–Se bond distances ranging from 2.78–2.93 Å. The Ag–S bond length is 2.71 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 7-coordinate geometry to one Au1+ and six Ag1+ atoms. In the second Se2- site, Se2- is bonded in a 7-coordinate geometry to one Au1+ and six Ag1+ atoms. In the third Se2- site, Se2- is bonded in a 7-coordinate geometry to one Au1+ and six Ag1+ atoms. S2- is bonded in a 7-coordinate geometry to one Au1+ and six Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag12Sn7H16(Se11N2)2 by Materials Project

Ag12Sn7Se22(NH4)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional and consists of sixteen ammonium molecules and one Ag12Sn7Se22 framework. In the Ag12Sn7Se22 framework, there are six inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.60–3.00 Å. In the second Ag1+ site, Ag1+ is bonded in a distorted trigonal planar geometry to three Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.60–2.72 Å. In the third Ag1+ site, Ag1+ is bonded to four Se2- atoms to form distorted AgSe4 tetrahedra that share corners with four SnSe4 tetrahedra. There are a spread of Ag–Se bond distances ranging from 2.64–2.99 Å. In the fourth Ag1+ site, Ag1+ is bonded in a distorted trigonal planar geometry to three Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.62–2.77 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to four Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.58–3.39 Å. In the sixth Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.61–2.73 Å. There are four inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with four equivalent AgSe4 tetrahedra. There are two shorter (2.59 Å) and two longer (2.60 Å) Sn–Se bond lengths. In the second Sn4+ site, Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with two equivalent AgSe4 tetrahedra and corners with two equivalent SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.51–2.63 Å. In the third Sn4+ site, Sn4+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are one shorter (2.53 Å) and three longer (2.59 Å) Sn–Se bond lengths. In the fourth Sn4+ site, Sn4+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.56–2.60 Å. There are eleven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Ag1+ and one Sn4+ atom to form distorted corner-sharing SeAg3Sn tetrahedra. In the second Se2- site, Se2- is bonded to three Ag1+ and one Sn4+ atom to form corner-sharing SeAg3Sn tetrahedra. In the third Se2- site, Se2- is bonded to three Ag1+ and one Sn4+ atom to form distorted corner-sharing SeAg3Sn tetrahedra. In the fourth Se2- site, Se2- is bonded in a water-like geometry to one Ag1+ and one Sn4+ atom. In the fifth Se2- site, Se2- is bonded in a water-like geometry to two Sn4+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and two Sn4+ atoms. In the seventh Se2- site, Se2- is bonded in a water-like geometry to one Ag1+ and one Sn4+ atom. In the eighth Se2- site, Se2- is bonded in a water-like geometry to two Sn4+ atoms. In the ninth Se2- site, Se2- is bonded in a 3-coordinate geometry to two Ag1+ and one Sn4+ atom. In the tenth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Ag1+ and one Sn4+ atom. In the eleventh Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ag1+ and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YbSe2 by Materials Project

YbSe2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Yb3+ is bonded in a 9-coordinate geometry to nine Se+1.50- atoms. There are a spread of Yb–Se bond distances ranging from 2.91–3.24 Å. There are two inequivalent Se+1.50- sites. In the first Se+1.50- site, Se+1.50- is bonded in a 8-coordinate geometry to four equivalent Yb3+ and four equivalent Se+1.50- atoms. All Se–Se bond lengths are 2.82 Å. In the second Se+1.50- site, Se+1.50- is bonded to five equivalent Yb3+ atoms to form a mixture of distorted edge and corner-sharing SeYb5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La4Ti2Se5O4 by Materials Project

La4Ti2O4Se5 crystallizes in the orthorhombic Cmc2_1 space group. The structure is two-dimensional and consists of two La4Ti2O4Se5 sheets oriented in the (0, 1, 0) direction. there are eight inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 3-coordinate geometry to four Se2- and three O2- atoms. There are two shorter (3.08 Å) and two longer (3.34 Å) La–Se bond lengths. There are two shorter (2.41 Å) and one longer (2.50 Å) La–O bond lengths. In the second La3+ site, La3+ is bonded in a 3-coordinate geometry to four Se2- and three O2- atoms. There are two shorter (3.10 Å) and two longer (3.34 Å) La–Se bond lengths. There are two shorter (2.40 Å) and one longer (2.48 Å) La–O bond lengths. In the third La3+ site, La3+ is bonded in a distorted bent 120 degrees geometry to four Se2- and two equivalent O2- atoms. There are two shorter (3.13 Å) and two longer (3.23 Å) La–Se bond lengths. Both La–O bond lengths are 2.27 Å. In the fourth La3+ site, La3+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.44 Å) and two longer (2.47 Å) La–O bond lengths. In the fifth La3+ site, La3+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.42 Å) and two longer (2.45 Å) La–O bond lengths. In the sixth La3+ site, La3+ is bonded in a 4-coordinate geometry to four Se2- and four O2- atoms. All La–Se bond lengths are 3.18 Å. There are two shorter (2.36 Å) and two longer (2.50 Å) La–O bond lengths. In the seventh La3+ site, La3+ is bonded in a 3-coordinate geometry to five Se2- and three O2- atoms. There are three shorter (3.15 Å) and two longer (3.33 Å) La–Se bond lengths. There are two shorter (2.44 Å) and one longer (2.49 Å) La–O bond lengths. In the eighth La3+ site, La3+ is bonded in a 3-coordinate geometry to five Se2- and three O2- atoms. There are three shorter (3.15 Å) and two longer (3.34 Å) La–Se bond lengths. There are two shorter (2.44 Å) and one longer (2.48 Å) La–O bond lengths. There are four inequivalent Ti3+ sites. In the first Ti3+ site, Ti3+ is bonded in a 6-coordinate geometry to four Se2- and two O2- atoms. There are two shorter (2.65 Å) and two longer (2.84 Å) Ti–Se bond lengths. There is one shorter (1.94 Å) and one longer (1.99 Å) Ti–O bond length. In the second Ti3+ site, Ti3+ is bonded in a 6-coordinate geometry to four Se2- and two O2- atoms. There are two shorter (2.64 Å) and two longer (2.85 Å) Ti–Se bond lengths. There is one shorter (1.95 Å) and one longer (1.98 Å) Ti–O bond length. In the third Ti3+ site, Ti3+ is bonded in a distorted linear geometry to four Se2- and two O2- atoms. There are two shorter (2.71 Å) and two longer (2.72 Å) Ti–Se bond lengths. There is one shorter (1.95 Å) and one longer (1.96 Å) Ti–O bond length. In the fourth Ti3+ site, Ti3+ is bonded to five Se2- and one O2- atom to form distorted edge-sharing TiSe5O octahedra. There are a spread of Ti–Se bond distances ranging from 2.59–2.67 Å. The Ti–O bond length is 1.89 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to four La3+ and two equivalent Ti3+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four La3+ and two equivalent Ti3+ atoms. In the third Se2- site, Se2- is bonded in a 1-coordinate geometry to one Ti3+ atom. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Ti3+ atoms. In the fifth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Ti3+ atoms. In the sixth Se2- site, Se2- is bonded in a 6-coordinate geometry to four La3+ and two equivalent Ti3+ atoms. In the seventh Se2- site, Se2- is bonded in a 6-coordinate geometry to four La3+ and two equivalent Ti3+ atoms. In the eighth Se2- site, Se2- is bonded in a 6-coordinate geometry to six La3+ atoms. In the ninth Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent La3+ and two equivalent Ti3+ atoms. In the tenth Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent La3+ and two equivalent Ti3+ atoms. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form a mixture of distorted edge and corner-sharing OLa3Ti tetrahedra. In the second O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form a mixture of distorted edge and corner-sharing OLa3Ti tetrahedra. In the third O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form a mixture of distorted edge and corner-sharing OLa3Ti tetrahedra. In the fourth O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form a mixture of distorted edge and corner-sharing OLa3Ti tetrahedra. In the fifth O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form distorted OLa3Ti tetrahedra that share corners with four OLa3Ti tetrahedra and edges with two equivalent OLa4 tetrahedra. In the sixth O2- site, O2- is bonded to three La3+ and one Ti3+ atom to form distorted OLa3Ti tetrahedra that share corners with four OLa3Ti tetrahedra and edges with two equivalent OLa4 tetrahedra. In the seventh O2- site, O2- is bonded to four La3+ atoms to form distorted OLa4 tetrahedra that share corners with two equivalent OLa4 tetrahedra and edges with four OLa3Ti tetrahedra. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to two equivalent La3+ and one Ti3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Reduction of selenite by bacterial exudates

Bacterial reduction of Se(IV) is a significant component of the global selenium cycle, and hence affects the fate and transport of selenium in both natural and contaminated environments. However, it is unknown whether bacterially-produced exudates are capable of reducing selenium independent of bacterial cells. In this study, we measured the rate and extent of Se(IV) reduction by exudates from three bacterial species, and we determined the importance of exudate sulfhydryl sites by conducting parallel experiments after treatment of the exudates with a sulfhydryl-specific blocking molecule. Here, we also conducted experiments with whole cell biomass for each of the three bacterial species to determine the importance of exudate-only reduction relative to whole biomass-promoted reduction. Under our experimental conditions, exudates from Bacillus subtilis and Pseudomonas putida remove Se(IV) from solution after an approximately 20-24 h lag period, but exudates from Shewanella oneidensis are ineffective at Se(IV) removal, except when the cells are grown in the presence of Se(IV). For both B. subtilis and P. putida , pretreatment blocking of the sulfhydryl sites on the exudate molecules dramatically decreases the rate and extent of Se(IV) removal, strongly suggesting that sulfhydryl groups on the exudate molecules play a key role in the Se(IV) reduction mechanism. The behavior of S. oneidensis exudates indicates that up-regulation of the Se(IV) reduction mechanism can occur in response to the Se content of the medium in which the cells grow. Our results demonstrate the capacity of some bacterial exudates to reduce Se(IV), and suggest that the activity of bacterial exudates should be accounted for when modeling selenium cycling in natural and engineered environments.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Revisiting Selenium Interactions with Pyrite: From Adsorption to Coprecipitation

Interactions of selenium (Se), a trace element bio-essential at low concentrations but highly toxic at high concentrations, with the most abundant sulfide mineral in the Earth's crust, namely pyrite, was investigated over a wide range of time scales. At the nanosecond scale, selenate Se(VI)O 4 2– adsorption onto the net pyrite surface is shown by ab-initio computations to proceed via the formation of a chemical bond between an oxyanion oxygen atom and a surface Fe atom, weakening the other Se-O bonds and reducing Se atom oxidation state. At the hour-to-day scale, adsorption and coprecipitation of selenate Se(VI)O 4 2– and selenite, Se(IV)O 3 2– , were investigated through wet chemical batch experiments at various pH values at different sulfide concentrations. Selenium removal from solution is slower and weaker for selenate than for selenite. After 24h, only 10% of selenate, against 60% of selenite (up to 100% in the presence of sulfide), is removed by the pyrite surface. Independently of its original oxidation state, adsorbed Se is completely reduced to elemental trigonal selenium via adsorption, precipitation or coprecipitation, as shown by XANES spectroscopy. Here, our EXAFS results, compared to published data on Se-rich pyrite, show a Se to S substitution within the pyrite structure. The reductive coprecipitation mechanism of selenium with pyrite represents valuable new insights for improving our understanding of modern and ancient biogeochemical cycles involving Se. In addition, several industries can benefit from direct applications of our findings, such as water treatment, green technologies and sustainable mining.

Adsorption↗
DOE OSTI2020

Materials Data on Ba4Nd2Cd3Se10 by Materials Project

Ba4Nd2Cd3Se10 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.31–3.78 Å. In the second Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with two equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, edges with three NdSe6 octahedra, edges with three equivalent BaSe7 pentagonal bipyramids, edges with four CdSe4 tetrahedra, and faces with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 17°. There are a spread of Ba–Se bond distances ranging from 3.29–3.45 Å. In the third Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with two equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, corners with five CdSe4 tetrahedra, corners with two equivalent CdSe4 trigonal pyramids, edges with three NdSe6 octahedra, edges with three equivalent BaSe7 pentagonal bipyramids, an edgeedge with one CdSe4 trigonal pyramid, and faces with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 22°. There are a spread of Ba–Se bond distances ranging from 3.30–3.51 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.28–3.71 Å. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to six Se2- atoms to form NdSe6 octahedra that share corners with two equivalent BaSe7 pentagonal bipyramids, edges with two equivalent NdSe6 octahedra, edges with three BaSe7 pentagonal bipyramids, edges with two equivalent CdSe4 tetrahedra, and edges with two equivalent CdSe4 trigonal pyramids. There are a spread of Nd–Se bond distances ranging from 2.96–3.04 Å. In the second Nd3+ site, Nd3+ is bonded to six Se2- atoms to form NdSe6 octahedra that share corners with two equivalent BaSe7 pentagonal bipyramids, corners with three equivalent CdSe4 tetrahedra, edges with two equivalent NdSe6 octahedra, and edges with three BaSe7 pentagonal bipyramids. There are three shorter (2.97 Å) and three longer (3.00 Å) Nd–Se bond lengths. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, corners with three CdSe4 tetrahedra, and edges with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 6–73°. There are a spread of Cd–Se bond distances ranging from 2.61–2.81 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form distorted CdSe4 trigonal pyramids that share corners with two equivalent BaSe7 pentagonal bipyramids, corners with two equivalent CdSe4 trigonal pyramids, edges with two equivalent NdSe6 octahedra, and an edgeedge with one BaSe7 pentagonal bipyramid. There are a spread of Cd–Se bond distances ranging from 2.58–2.84 Å. In the third Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent BaSe7 pentagonal bipyramids, corners with three CdSe4 tetrahedra, edges with two equivalent NdSe6 octahedra, and edges with two equivalent BaSe7 pentagonal bipyramids. There are a spread of Cd–Se bond distances ranging from 2.67–2.78 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Ba2+ and two equivalent Nd3+ atoms to form distorted SeBa3Nd2 trigonal bipyramids that share corners with six SeBa4Cd square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa4NdCd octahedra, edges with two SeBa2NdCd2 square pyramids, and edges with three SeBa3Nd2 trigonal bipyramids. In the second Se2- site, Se2- is bonded to three Ba2+ and two equivalent Nd3+ atoms to form distorted SeBa3Nd2 trigonal bipyramids that share corners with four equivalent SeBa4Cd2 octahedra, corners with two equivalent SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with five SeBa4Cd2 octahedra, an edgeedge with one SeBa2NdCd2 square pyramid, and edges with three SeBa3Nd2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 40–50°. In the third Se2- site, Se2- is bonded to two equivalent Ba2+, one Nd3+, and two equivalent Cd2+ atoms to form distorted SeBa2NdCd2 square pyramids that share corners with two equivalent SeBa4Cd2 octahedra, corners with three SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa3Nd2Cd octahedra, edges with three SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 60°. In the fourth Se2- site, Se2- is bonded to two equivalent Ba2+, one Nd3+, and two equivalent Cd2+ atoms to form distorted SeBa2NdCd2 square pyramids that share corners with two equivalent SeBa4Cd2 octahedra, corners with three SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with three SeBa4Cd2 octahedra, edges with two equivalent SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 53°. In the fifth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Ba2+, one Nd3+, and two equivalent Cd2+ atoms. In the sixth Se2- site, Se2- is bonded to four Ba2+ and one Cd2+ atom to form distorted SeBa4Cd square pyramids that share corners with two equivalent SeBa4NdCd octahedra, corners with four SeBa2NdCd2 square pyramids, corners with four equivalent SeBa3Nd2 trigonal bipyramids, an edgeedge with one SeBa4NdCd octahedra, edges with three SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 41°. In the seventh Se2- site, Se2- is bonded to four Ba2+ and two Cd2+ atoms to form distorted SeBa4Cd2 octahedra that share corners with six SeBa4NdCd octahedra, corners with four SeBa2NdCd2 square pyramids, corners with four equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa4Cd2 octahedra, an edgeedge with one SeBa2NdCd2 square pyramid, an edgeedge with one SeBa3Nd2 trigonal bipyramid, and faces with two SeBa4NdCd octahedra. The corner-sharing octahedra tilt angles range from 41–58°. In the eighth Se2- site, Se2- is bonded to four Ba2+, one Nd3+, and one Cd2+ atom to form SeBa4NdCd octahedra that share corners with four SeBa4Cd2 octahedra, corners with two equivalent SeBa4Cd square pyramids, edges with three SeBa4NdCd octahedra, an edgeedge with one SeBa4Cd square pyramid, edges with four SeBa3Nd2 trigonal bipyramids, and a faceface with one SeBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 22–53°. In the ninth Se2- site, Se2- is bonded in a 6-coordinate geometry to three Ba2+, two equivalent Nd3+, and one Cd2+ atom. In the tenth Se2- site, Se2- is bonded to three Ba2+, two equivalent Nd3+, and one Cd2+ atom to form distorted SeBa3Nd2Cd octahedra that share corners with six SeBa4Cd2 octahedra, edges with three SeBa4NdCd octahedra, edges with four SeBa2NdCd2 square pyramids, edges with two equivalent SeBa3Nd2 trigonal bipyramids, and a faceface with one SeBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 22–58°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbBSe3 by Materials Project

RbBSe3 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four rubidium molecules and two BSe3 ribbons oriented in the (1, 0, 0) direction. In each BSe3 ribbon, B3- is bonded to four Se+0.67+ atoms to form corner-sharing BSe4 tetrahedra. There are two shorter (2.06 Å) and two longer (2.09 Å) B–Se bond lengths. There are three inequivalent Se+0.67+ sites. In the first Se+0.67+ site, Se+0.67+ is bonded in a single-bond geometry to one B3- atom. In the second Se+0.67+ site, Se+0.67+ is bonded in a water-like geometry to two equivalent B3- atoms. In the third Se+0.67+ site, Se+0.67+ is bonded in a single-bond geometry to one B3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZrSe3 by Materials Project

ZrSe3 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one ZrSe3 sheet oriented in the (0, 0, 1) direction. Zr4+ is bonded in a 8-coordinate geometry to eight Se+1.33- atoms. There are a spread of Zr–Se bond distances ranging from 2.76–2.91 Å. There are three inequivalent Se+1.33- sites. In the first Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to two equivalent Zr4+ atoms. In the second Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to two equivalent Zr4+ atoms. In the third Se+1.33- site, Se+1.33- is bonded to four equivalent Zr4+ atoms to form a mixture of distorted edge and corner-sharing SeZr4 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl5Se3 by Materials Project

Tl5Se3 crystallizes in the tetragonal P4/ncc space group. The structure is three-dimensional. there are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 5-coordinate geometry to five Se+1.67- atoms. There are a spread of Tl–Se bond distances ranging from 3.03–3.56 Å. In the second Tl1+ site, Tl1+ is bonded to six Se+1.67- atoms to form corner-sharing TlSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–40°. There are one shorter (3.17 Å) and five longer (3.24 Å) Tl–Se bond lengths. There are two inequivalent Se+1.67- sites. In the first Se+1.67- site, Se+1.67- is bonded in a 8-coordinate geometry to eight Tl1+ atoms. In the second Se+1.67- site, Se+1.67- is bonded in a 10-coordinate geometry to ten Tl1+ atoms.

36 MATERIALS SCIENCE↗