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DOE OSTI2020

Materials Data on Ba(BiS2)2 by Materials Project

Ba(BiS2)2 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.19–3.48 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.21–3.57 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are a spread of Bi–S bond distances ranging from 2.71–3.01 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of distorted edge and corner-sharing BiS6 square pyramids. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Bi–S bond distances ranging from 2.59–3.56 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of distorted edge and corner-sharing BiS6 octahedra. There are a spread of Bi–S bond distances ranging from 2.57–3.48 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. There are a spread of Bi–S bond distances ranging from 2.65–3.02 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to one Ba2+ and five Bi3+ atoms to form distorted SBaBi5 octahedra that share corners with two equivalent SBaBi5 octahedra, corners with four SBa2Bi3 trigonal bipyramids, edges with seven SBaBi5 octahedra, and edges with three SBa2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 5°. In the second S2- site, S2- is bonded in a distorted trigonal planar geometry to three equivalent Bi3+ atoms. In the third S2- site, S2- is bonded to two Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with four SBaBi5 octahedra, corners with three equivalent SBa2Bi3 square pyramids, corners with two equivalent SBa2Bi3 trigonal bipyramids, edges with three SBaBi5 octahedra, and edges with four SBa2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 10–48°. In the fourth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with four equivalent SBaBi5 octahedra, corners with two equivalent SBa2Bi3 square pyramids, corners with two equivalent SBa4Bi trigonal bipyramids, an edgeedge with one SBaBi5 octahedra, edges with three equivalent SBa2Bi3 square pyramids, and edges with five SBa2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 6–41°. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Ba2+ and one Bi3+ atom. In the sixth S2- site, S2- is bonded to one Ba2+ and five Bi3+ atoms to form distorted SBaBi5 octahedra that share corners with two equivalent SBaBi5 octahedra, corners with five SBa2Bi3 trigonal bipyramids, edges with five SBaBi5 octahedra, edges with two equivalent SBa2Bi3 square pyramids, and edges with five SBa2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 5°. In the seventh S2- site, S2- is bonded to four Ba2+ and one Bi3+ atom to form distorted SBa4Bi trigonal bipyramids that share a cornercorner with one SBaBi5 octahedra, corners with two equivalent SBa2Bi3 square pyramids, corners with two equivalent SBa2Bi3 trigonal bipyramids, edges with four SBaBi5 octahedra, an edgeedge with one SBa2Bi3 square pyramid, and edges with five SBa2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. In the eighth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 square pyramids that share corners with seven SBa2Bi3 trigonal bipyramids, edges with two equivalent SBaBi5 octahedra, edges with two equivalent SBa2Bi3 square pyramids, and edges with four SBa2Bi3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BiS2 by Materials Project

BiS2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five S+1.50- atoms. There are a spread of Bi–S bond distances ranging from 2.64–2.94 Å. In the second Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six S+1.50- atoms. There are a spread of Bi–S bond distances ranging from 2.64–3.36 Å. There are four inequivalent S+1.50- sites. In the first S+1.50- site, S+1.50- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Bi3+ and one S+1.50- atom. The S–S bond length is 2.07 Å. In the second S+1.50- site, S+1.50- is bonded in a 3-coordinate geometry to two equivalent Bi3+ and one S+1.50- atom. The S–S bond length is 2.06 Å. In the third S+1.50- site, S+1.50- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the fourth S+1.50- site, S+1.50- is bonded in a 3-coordinate geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(BiS2)2 by Materials Project

Sr(BiS2)2 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 3.12–3.46 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sr–S bond distances ranging from 3.07–3.31 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent BiS5 square pyramids, edges with six BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.63–3.04 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form distorted BiS6 octahedra that share corners with four equivalent BiS5 square pyramids, edges with four BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.56–3.52 Å. In the third Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with six BiS6 octahedra, edges with two BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 3–83°. There are a spread of Bi–S bond distances ranging from 2.59–2.89 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are a spread of Bi–S bond distances ranging from 2.69–3.04 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to four equivalent Sr2+ and one Bi3+ atom to form distorted SSr4Bi square pyramids that share a cornercorner with one SSrBi5 octahedra, corners with ten SSr4Bi square pyramids, corners with two equivalent SSr2Bi3 trigonal bipyramids, edges with eight SSrBi4 square pyramids, and edges with two equivalent SSr2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the second S2- site, S2- is bonded to two Sr2+ and three Bi3+ atoms to form distorted SSr2Bi3 trigonal bipyramids that share a cornercorner with one SSrBi5 octahedra, corners with eight SSr4Bi square pyramids, corners with two equivalent SSr2Bi3 trigonal bipyramids, edges with two equivalent SSrBi5 octahedra, edges with five SSr4Bi square pyramids, and edges with two equivalent SSr2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. In the third S2- site, S2- is bonded to two equivalent Sr2+ and three Bi3+ atoms to form distorted SSr2Bi3 trigonal bipyramids that share corners with four equivalent SSrBi5 octahedra, corners with four SSr2Bi3 square pyramids, an edgeedge with one SSrBi5 octahedra, edges with four SSr4Bi square pyramids, and edges with four SSr2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 5–43°. In the fourth S2- site, S2- is bonded to four Sr2+ and one Bi3+ atom to form distorted SSr4Bi square pyramids that share corners with six SSr4Bi square pyramids, corners with two equivalent SSr2Bi3 trigonal bipyramids, edges with two equivalent SSrBi5 octahedra, edges with seven SSr4Bi square pyramids, and edges with three SSr2Bi3 trigonal bipyramids. In the fifth S2- site, S2- is bonded in a distorted trigonal planar geometry to three equivalent Bi3+ atoms. In the sixth S2- site, S2- is bonded to one Sr2+ and four Bi3+ atoms to form distorted SSrBi4 square pyramids that share corners with four equivalent SSrBi5 octahedra, corners with two equivalent SSr4Bi square pyramids, corners with three equivalent SSr2Bi3 trigonal bipyramids, an edgeedge with one SSrBi5 octahedra, edges with six SSr4Bi square pyramids, and an edgeedge with one SSr2Bi3 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 5–95°. In the seventh S2- site, S2- is bonded to two equivalent Sr2+ and three Bi3+ atoms to form distorted SSr2Bi3 square pyramids that share corners with two equivalent SSr4Bi square pyramids, corners with five SSr2Bi3 trigonal bipyramids, edges with two equivalent SSrBi5 octahedra, edges with three SSr4Bi square pyramids, and edges with three equivalent SSr2Bi3 trigonal bipyramids. In the eighth S2- site, S2- is bonded to one Sr2+ and five Bi3+ atoms to form distorted SSrBi5 octahedra that share corners with five SSrBi4 square pyramids, corners with five SSr2Bi3 trigonal bipyramids, edges with two equivalent SSrBi5 octahedra, edges with five SSr4Bi square pyramids, and edges with three SSr2Bi3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(BiS2)2 by Materials Project

Ba(BiS2)2 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are five inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are six shorter (3.29 Å) and three longer (3.59 Å) Ba–S bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are six shorter (3.29 Å) and three longer (3.59 Å) Ba–S bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are three shorter (3.25 Å) and six longer (3.54 Å) Ba–S bond lengths. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.23–3.33 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.23–3.33 Å. There are six inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with four BiS6 octahedra, an edgeedge with one BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 5–87°. There are a spread of Bi–S bond distances ranging from 2.58–3.02 Å. In the second Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with four BiS6 octahedra, an edgeedge with one BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 5–87°. There are a spread of Bi–S bond distances ranging from 2.59–3.02 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four BiS5 square pyramids, edges with four BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.70–3.00 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four BiS5 square pyramids, edges with four BiS6 octahedra, and an edgeedge with one BiS5 square pyramid. There are a spread of Bi–S bond distances ranging from 2.71–2.98 Å. In the fifth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Bi–S bond distances ranging from 2.76–2.93 Å. In the sixth Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Bi–S bond distances ranging from 2.74–2.92 Å. There are twelve inequivalent S2- sites. In the first S2- site, S2- is bonded to two Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with ten SBa2Bi3 square pyramids, corners with four equivalent SBa2Bi3 trigonal bipyramids, edges with five SBaBi4 square pyramids, and edges with two equivalent SBa2Bi3 trigonal bipyramids. In the second S2- site, S2- is bonded to two Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with ten SBa2Bi3 square pyramids, corners with four equivalent SBa2Bi3 trigonal bipyramids, edges with five SBa4Bi square pyramids, and edges with two equivalent SBa2Bi3 trigonal bipyramids. In the third S2- site, S2- is bonded to one Ba2+ and three Bi3+ atoms to form distorted SBaBi3 tetrahedra that share corners with four SBa2Bi3 square pyramids, corners with four equivalent SBaBi3 tetrahedra, corners with three SBa2Bi3 trigonal bipyramids, and an edgeedge with one SBa2Bi3 square pyramid. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Ba2+ and three Bi3+ atoms. In the fifth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 square pyramids that share corners with two equivalent SBa4Bi square pyramids, corners with two equivalent SBaBi3 tetrahedra, corners with five SBa2Bi3 trigonal bipyramids, edges with five SBa2Bi3 square pyramids, an edgeedge with one SBaBi3 tetrahedra, and edges with three SBa2Bi3 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 square pyramids that share corners with two equivalent SBa4Bi square pyramids, corners with two equivalent SBaBi3 tetrahedra, corners with five SBa2Bi3 trigonal bipyramids, edges with five SBa2Bi3 square pyramids, and edges with three SBa2Bi3 trigonal bipyramids. In the seventh S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with eight SBa2Bi3 square pyramids, a cornercorner with one SBaBi3 tetrahedra, edges with five SBa2Bi3 square pyramids, and edges with four SBa2Bi3 trigonal bipyramids. In the eighth S2- site, S2- is bonded to two equivalent Ba2+ and three Bi3+ atoms to form distorted SBa2Bi3 trigonal bipyramids that share corners with eight SBa2Bi3 square pyramids, corners with two equivalent SBaBi3 tetrahedra, edges with five SBa2Bi3 square pyramids, and edges with four SBa2Bi3 trigonal bipyramids. In the ninth S2- site, S2- is bonded to one Ba2+ and four Bi3+ atoms to form a mixture of distorted edge and corner-sharing SBaBi4 square pyramids. In the tenth S2- site, S2- is bonded to one Ba2+ and four Bi3+ atoms to form a mixture of distorted edge and corner-sharing SBaBi4 square pyramids. In the eleventh S2- site, S2- is bonded to four Ba2+ and one Bi3+ atom to form distorted SBa4Bi square pyramids that share corners with six SBa4Bi square pyramids, corners with four SBa2Bi3 trigonal bipyramids, edges with seven SBa2Bi3 square pyramids, and edges with five SBa2Bi3 trigonal bipyramids. In the twelfth S2- site, S2- is bonded to four Ba2+ and one Bi3+ atom to form a mixture of distorted edge and corner-sharing SBa4Bi square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu(BiS2)2 by Materials Project

Eu(BiS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Eu2+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of Eu–S bond distances ranging from 3.00–3.54 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three equivalent BiS7 pentagonal bipyramids, edges with four equivalent BiS6 octahedra, and edges with two equivalent BiS7 pentagonal bipyramids. There are a spread of Bi–S bond distances ranging from 2.67–3.07 Å. In the second Bi3+ site, Bi3+ is bonded to seven S2- atoms to form distorted BiS7 pentagonal bipyramids that share corners with three equivalent BiS6 octahedra, edges with two equivalent BiS6 octahedra, and edges with four equivalent BiS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 6–49°. There are a spread of Bi–S bond distances ranging from 2.82–3.14 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Eu2+ and four Bi3+ atoms to form distorted SEu2Bi4 octahedra that share corners with four equivalent SEu2Bi3 square pyramids, corners with three equivalent SEu2Bi3 trigonal bipyramids, edges with four equivalent SEu2Bi4 octahedra, edges with three equivalent SEu2Bi3 trigonal bipyramids, and a faceface with one SEu2Bi3 square pyramid. In the second S2- site, S2- is bonded to two equivalent Eu2+ and three Bi3+ atoms to form distorted SEu2Bi3 trigonal bipyramids that share corners with three equivalent SEu2Bi4 octahedra, corners with six equivalent SEu2Bi3 square pyramids, edges with three equivalent SEu2Bi4 octahedra, edges with two equivalent SEu2Bi3 square pyramids, and edges with two equivalent SEu2Bi3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 4–27°. In the third S2- site, S2- is bonded to two equivalent Eu2+ and three equivalent Bi3+ atoms to form distorted SEu2Bi3 square pyramids that share corners with four equivalent SEu2Bi4 octahedra, corners with six equivalent SEu2Bi3 trigonal bipyramids, edges with four equivalent SEu2Bi3 square pyramids, edges with two equivalent SEu2Bi3 trigonal bipyramids, and a faceface with one SEu2Bi4 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Eu2+ and three Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Yb(BiS2)2 by Materials Project

Yb(BiS2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Yb2+ is bonded to seven S2- atoms to form distorted YbS7 pentagonal bipyramids that share corners with four equivalent BiS6 octahedra, corners with four equivalent BiS7 pentagonal bipyramids, edges with three equivalent BiS6 octahedra, edges with three equivalent BiS7 pentagonal bipyramids, a faceface with one BiS7 pentagonal bipyramid, and faces with two equivalent YbS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 5–71°. There are a spread of Yb–S bond distances ranging from 2.90–3.03 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three equivalent BiS7 pentagonal bipyramids, corners with four equivalent YbS7 pentagonal bipyramids, edges with four equivalent BiS6 octahedra, edges with two equivalent BiS7 pentagonal bipyramids, and edges with three equivalent YbS7 pentagonal bipyramids. There are a spread of Bi–S bond distances ranging from 2.68–3.08 Å. In the second Bi3+ site, Bi3+ is bonded to seven S2- atoms to form distorted BiS7 pentagonal bipyramids that share corners with three equivalent BiS6 octahedra, corners with four equivalent YbS7 pentagonal bipyramids, edges with two equivalent BiS6 octahedra, edges with three equivalent YbS7 pentagonal bipyramids, edges with four equivalent BiS7 pentagonal bipyramids, and a faceface with one YbS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 9–49°. There are a spread of Bi–S bond distances ranging from 2.81–3.14 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Yb2+ and four Bi3+ atoms to form distorted SYb2Bi4 octahedra that share corners with four equivalent SYb2Bi3 square pyramids, corners with three equivalent SYbBi3 trigonal pyramids, edges with four equivalent SYb2Bi4 octahedra, edges with three equivalent SYbBi3 trigonal pyramids, and a faceface with one SYb2Bi3 square pyramid. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Yb2+ and three Bi3+ atoms. In the third S2- site, S2- is bonded to two equivalent Yb2+ and three equivalent Bi3+ atoms to form distorted SYb2Bi3 square pyramids that share corners with four equivalent SYb2Bi4 octahedra, corners with five equivalent SYbBi3 trigonal pyramids, edges with four equivalent SYb2Bi3 square pyramids, and a faceface with one SYb2Bi4 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. In the fourth S2- site, S2- is bonded to one Yb2+ and three Bi3+ atoms to form distorted SYbBi3 trigonal pyramids that share corners with three equivalent SYb2Bi4 octahedra, corners with five equivalent SYb2Bi3 square pyramids, corners with two equivalent SYbBi3 trigonal pyramids, and edges with three equivalent SYb2Bi4 octahedra. The corner-sharing octahedra tilt angles range from 5–36°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu4(BiS2)5 by Materials Project

Cu4Bi5S10 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cu+1.25+ sites. In the first Cu+1.25+ site, Cu+1.25+ is bonded to four S2- atoms to form a mixture of edge and corner-sharing CuS4 tetrahedra. There are three shorter (2.31 Å) and one longer (2.36 Å) Cu–S bond lengths. In the second Cu+1.25+ site, Cu+1.25+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with three equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 1–75°. There are a spread of Cu–S bond distances ranging from 2.28–2.47 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Bi–S bond distances ranging from 2.64–3.37 Å. In the second Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to seven S2- atoms. There are a spread of Bi–S bond distances ranging from 2.67–3.55 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with six equivalent CuS4 tetrahedra and edges with two equivalent BiS6 octahedra. All Bi–S bond lengths are 2.83 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Cu+1.25+ and two equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing SCu2Bi2 trigonal pyramids. In the second S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent Cu+1.25+ and three Bi3+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Cu+1.25+ and three equivalent Bi3+ atoms. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to one Cu+1.25+ and four Bi3+ atoms. In the fifth S2- site, S2- is bonded in a 3-coordinate geometry to five Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(BiS2)2 by Materials Project

HgBi2S4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to six S2- atoms to form distorted HgS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with two equivalent HgS6 octahedra, and edges with six equivalent BiS7 square pyramids. The corner-sharing octahedral tilt angles are 66°. There are two shorter (2.40 Å) and four longer (3.24 Å) Hg–S bond lengths. In the second Hg2+ site, Hg2+ is bonded to six S2- atoms to form distorted HgS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with two equivalent HgS6 octahedra, and edges with six equivalent BiS6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two shorter (2.39 Å) and four longer (3.27 Å) Hg–S bond lengths. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three HgS6 octahedra, corners with four equivalent BiS7 square pyramids, edges with three equivalent HgS6 octahedra, edges with four equivalent BiS6 octahedra, and an edgeedge with one BiS7 square pyramid. The corner-sharing octahedra tilt angles range from 8–66°. There are a spread of Bi–S bond distances ranging from 2.65–3.17 Å. In the second Bi3+ site, Bi3+ is bonded to seven S2- atoms to form distorted BiS7 square pyramids that share corners with four HgS6 octahedra, corners with four equivalent BiS6 octahedra, an edgeedge with one BiS6 octahedra, edges with three equivalent HgS6 octahedra, edges with two equivalent BiS7 square pyramids, and faces with two equivalent BiS7 square pyramids. The corner-sharing octahedra tilt angles range from 9–64°. There are a spread of Bi–S bond distances ranging from 2.62–3.48 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to one Hg2+ and four Bi3+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Hg2+ and three equivalent Bi3+ atoms. In the third S2- site, S2- is bonded to one Hg2+ and three Bi3+ atoms to form distorted SHgBi3 tetrahedra that share corners with three equivalent SHg2Bi3 square pyramids and corners with three equivalent SHgBi3 tetrahedra. In the fourth S2- site, S2- is bonded to two equivalent Hg2+ and three equivalent Bi3+ atoms to form distorted SHg2Bi3 square pyramids that share corners with two equivalent SHg2Bi3 square pyramids, corners with three equivalent SHgBi3 tetrahedra, and edges with five equivalent SHg2Bi3 square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb3Cu2(BiS2)5 by Materials Project

Rb3Bi5Cu2S10 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Rb–S bond distances ranging from 3.37–3.76 Å. In the second Rb1+ site, Rb1+ is bonded to six S2- atoms to form distorted RbS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, edges with two equivalent RbS6 octahedra, and edges with six BiS6 octahedra. The corner-sharing octahedral tilt angles are 16°. All Rb–S bond lengths are 3.30 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one RbS6 octahedra, a cornercorner with one BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four BiS6 octahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Cu–S bond distances ranging from 2.34–2.68 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three BiS6 octahedra, edges with two equivalent RbS6 octahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 6–42°. There are a spread of Bi–S bond distances ranging from 2.68–3.13 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one BiS6 octahedra, corners with two equivalent RbS6 octahedra, an edgeedge with one RbS6 octahedra, edges with six BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–42°. There are a spread of Bi–S bond distances ranging from 2.70–3.03 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with eight BiS6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are two shorter (2.84 Å) and four longer (2.87 Å) Bi–S bond lengths. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Rb1+, one Cu1+, and three Bi3+ atoms to form distorted SRb2CuBi3 octahedra that share corners with three SRb3CuBi2 octahedra, corners with two equivalent SRb2Bi3 square pyramids, edges with six SRbBi5 octahedra, an edgeedge with one SRb2Bi3 square pyramid, and a faceface with one SRb3CuBi2 octahedra. The corner-sharing octahedra tilt angles range from 0–71°. In the second S2- site, S2- is bonded to three Rb1+, one Cu1+, and two equivalent Bi3+ atoms to form distorted SRb3CuBi2 octahedra that share corners with seven SRb2CuBi3 octahedra, corners with two equivalent SRb2Bi3 square pyramids, edges with three SRbBi5 octahedra, edges with two equivalent SRb2Bi3 square pyramids, and a faceface with one SRb2CuBi3 octahedra. The corner-sharing octahedra tilt angles range from 0–71°. In the third S2- site, S2- is bonded to two equivalent Rb1+ and three Bi3+ atoms to form SRb2Bi3 square pyramids that share corners with four SRb3CuBi2 octahedra, corners with two equivalent SRb2Bi3 square pyramids, edges with five SRbBi5 octahedra, and edges with three equivalent SRb2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 7–73°. In the fourth S2- site, S2- is bonded to one Rb1+ and five Bi3+ atoms to form SRbBi5 octahedra that share corners with six SRbBi5 octahedra, edges with eight SRb2CuBi3 octahedra, and edges with two equivalent SRb2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 0–44°. In the fifth S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Rb1+, two equivalent Cu1+, and two Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Cu2(BiS2)5 by Materials Project

K3Bi5Cu2S10 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.26–3.74 Å. In the second K1+ site, K1+ is bonded to six S2- atoms to form distorted KS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, edges with two equivalent KS6 octahedra, and edges with six BiS6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are two shorter (3.16 Å) and four longer (3.17 Å) K–S bond lengths. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one KS6 octahedra, a cornercorner with one BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four BiS6 octahedra. The corner-sharing octahedra tilt angles range from 5–14°. There are a spread of Cu–S bond distances ranging from 2.35–2.64 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one BiS6 octahedra, corners with two equivalent KS6 octahedra, an edgeedge with one KS6 octahedra, edges with six BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–44°. There are a spread of Bi–S bond distances ranging from 2.71–3.02 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three BiS6 octahedra, edges with two equivalent KS6 octahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–44°. There are a spread of Bi–S bond distances ranging from 2.70–3.07 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with eight BiS6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two shorter (2.84 Å) and four longer (2.86 Å) Bi–S bond lengths. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent Cu1+, and two Bi3+ atoms. In the second S2- site, S2- is bonded to one K1+ and five Bi3+ atoms to form SKBi5 octahedra that share corners with six SKBi5 octahedra, edges with eight SKBi5 octahedra, and edges with two equivalent SK2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 0–43°. In the third S2- site, S2- is bonded to two equivalent K1+ and three Bi3+ atoms to form SK2Bi3 square pyramids that share corners with four SK2CuBi3 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with five SK2CuBi3 octahedra, and edges with three equivalent SK2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 6–77°. In the fourth S2- site, S2- is bonded to two equivalent K1+, one Cu1+, and three Bi3+ atoms to form distorted SK2CuBi3 octahedra that share corners with three SK2CuBi3 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with six SK2CuBi3 octahedra, an edgeedge with one SK2Bi3 square pyramid, and a faceface with one SK3CuBi2 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. In the fifth S2- site, S2- is bonded to three K1+, one Cu1+, and two equivalent Bi3+ atoms to form distorted SK3CuBi2 octahedra that share corners with seven SKBi5 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with three SKBi5 octahedra, edges with two equivalent SK2Bi3 square pyramids, and a faceface with one SK2CuBi3 octahedra. The corner-sharing octahedra tilt angles range from 0–68°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCu(BiS2)2 by Materials Project

KBi2CuS4 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. K1+ is bonded to seven S2- atoms to form distorted KS7 pentagonal bipyramids that share corners with eight BiS6 octahedra, corners with two equivalent CuS4 trigonal pyramids, edges with six BiS6 octahedra, edges with three equivalent CuS4 trigonal pyramids, and faces with two equivalent KS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 18–74°. There are a spread of K–S bond distances ranging from 3.26–3.43 Å. Cu1+ is bonded to four S2- atoms to form CuS4 trigonal pyramids that share corners with two BiS6 octahedra, corners with two equivalent KS7 pentagonal bipyramids, corners with two equivalent CuS4 trigonal pyramids, edges with four BiS6 octahedra, and edges with three equivalent KS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 3–15°. There are a spread of Cu–S bond distances ranging from 2.30–2.71 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three equivalent BiS6 octahedra, corners with four equivalent KS7 pentagonal bipyramids, a cornercorner with one CuS4 trigonal pyramid, edges with five BiS6 octahedra, edges with three equivalent KS7 pentagonal bipyramids, and edges with two equivalent CuS4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 6–35°. There are a spread of Bi–S bond distances ranging from 2.71–3.13 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three equivalent BiS6 octahedra, corners with four equivalent KS7 pentagonal bipyramids, a cornercorner with one CuS4 trigonal pyramid, edges with five BiS6 octahedra, edges with three equivalent KS7 pentagonal bipyramids, and edges with two equivalent CuS4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 6–35°. There are a spread of Bi–S bond distances ranging from 2.69–3.08 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to one K1+ and four Bi3+ atoms to form SKBi4 square pyramids that share corners with eight SK2CuBi3 octahedra, edges with four SK2CuBi3 octahedra, and edges with two equivalent SKBi4 square pyramids. The corner-sharing octahedra tilt angles range from 0–82°. In the second S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent Cu1+, and two Bi3+ atoms. In the third S2- site, S2- is bonded to two equivalent K1+, one Cu1+, and three Bi3+ atoms to form distorted SK2CuBi3 octahedra that share corners with two equivalent SK2CuBi3 octahedra, corners with six equivalent SKBi4 square pyramids, edges with four SK2CuBi3 octahedra, an edgeedge with one SKBi4 square pyramid, and a faceface with one SK2CuBi3 octahedra. The corner-sharing octahedral tilt angles are 65°. In the fourth S2- site, S2- is bonded to two equivalent K1+, one Cu1+, and three Bi3+ atoms to form distorted SK2CuBi3 octahedra that share corners with two equivalent SK2CuBi3 octahedra, corners with two equivalent SKBi4 square pyramids, edges with four SK2CuBi3 octahedra, edges with three equivalent SKBi4 square pyramids, and a faceface with one SK2CuBi3 octahedra. The corner-sharing octahedral tilt angles are 65°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsCu(BiS2)2 by Materials Project

CsBi2CuS4 crystallizes in the orthorhombic Cmc2_1 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 3.47–3.77 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four BiS6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Cu–S bond distances ranging from 2.28–2.72 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three equivalent BiS6 octahedra, a cornercorner with one CuS4 tetrahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 3–25°. There are a spread of Bi–S bond distances ranging from 2.67–3.12 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form distorted BiS6 octahedra that share corners with three equivalent BiS6 octahedra, a cornercorner with one CuS4 tetrahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 3–25°. There are a spread of Bi–S bond distances ranging from 2.67–3.27 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to one Cs1+ and four Bi3+ atoms to form distorted SCsBi4 square pyramids that share corners with eight SCs2CuBi3 octahedra, edges with four SCs2CuBi3 octahedra, and edges with two equivalent SCsBi4 square pyramids. The corner-sharing octahedra tilt angles range from 2–81°. In the second S2- site, S2- is bonded to two equivalent Cs1+, one Cu1+, and three Bi3+ atoms to form distorted SCs2CuBi3 octahedra that share corners with two equivalent SCs2CuBi3 octahedra, corners with six equivalent SCsBi4 square pyramids, edges with four SCs2CuBi3 octahedra, an edgeedge with one SCsBi4 square pyramid, and a faceface with one SCs2CuBi3 octahedra. The corner-sharing octahedral tilt angles are 68°. In the third S2- site, S2- is bonded to two equivalent Cs1+, one Cu1+, and three Bi3+ atoms to form distorted SCs2CuBi3 octahedra that share corners with two equivalent SCs2CuBi3 octahedra, corners with two equivalent SCsBi4 square pyramids, edges with four SCs2CuBi3 octahedra, edges with three equivalent SCsBi4 square pyramids, and a faceface with one SCs2CuBi3 octahedra. The corner-sharing octahedral tilt angles are 68°. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Cu1+, and two Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs3Cu2(BiS2)5 by Materials Project

Cs3Bi5Cu2S10 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are four shorter (3.44 Å) and two longer (3.46 Å) Cs–S bond lengths. In the second Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Cs–S bond distances ranging from 3.48–3.80 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four BiS6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are a spread of Cu–S bond distances ranging from 2.34–2.69 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one BiS6 octahedra, edges with six BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are a spread of Bi–S bond distances ranging from 2.68–3.08 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form distorted BiS6 octahedra that share corners with three BiS6 octahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 8–41°. There are a spread of Bi–S bond distances ranging from 2.65–3.24 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with eight BiS6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are two shorter (2.85 Å) and four longer (2.90 Å) Bi–S bond lengths. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded to three Cs1+, one Cu1+, and two equivalent Bi3+ atoms to form distorted SCs3CuBi2 octahedra that share corners with seven SCs3CuBi2 octahedra, corners with two equivalent SCs2Bi3 square pyramids, edges with three SCs3CuBi2 octahedra, edges with two equivalent SCs2Bi3 square pyramids, and a faceface with one SCs2CuBi3 octahedra. The corner-sharing octahedra tilt angles range from 0–74°. In the second S2- site, S2- is bonded to two equivalent Cs1+, one Cu1+, and three Bi3+ atoms to form distorted SCs2CuBi3 octahedra that share corners with three SCs3CuBi2 octahedra, corners with two equivalent SCs2Bi3 square pyramids, edges with six SCs2CuBi3 octahedra, an edgeedge with one SCs2Bi3 square pyramid, and a faceface with one SCs3CuBi2 octahedra. The corner-sharing octahedra tilt angles range from 0–74°. In the third S2- site, S2- is bonded to one Cs1+ and five Bi3+ atoms to form SCsBi5 octahedra that share corners with six SCs3CuBi2 octahedra, edges with eight SCs3CuBi2 octahedra, and edges with two equivalent SCs2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 0–46°. In the fourth S2- site, S2- is bonded to two equivalent Cs1+ and three Bi3+ atoms to form SCs2Bi3 square pyramids that share corners with four SCs3CuBi2 octahedra, corners with two equivalent SCs2Bi3 square pyramids, edges with five SCs3CuBi2 octahedra, and edges with three equivalent SCs2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 6–69°. In the fifth S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Cu1+, and two Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Prediction of BiS2-type pnictogen dichalcogenide monolayers for optoelectronics

Abstract In this work, we introduce a 2D materials family with chemical formula MX 2 (M={As, Sb, Bi} and X={S, Se, Te}) having a rectangular 2D lattice. This materials family has been predicted by systematic ab-initio structure search calculations in two dimensions. Using density-functional theory and many-body perturbation theory, we study the structural, vibrational, electronic, optical, and excitonic properties of the predicted MX 2 family. Our calculations reveal that the predicted SbX 2 and BiX 2 monolayers are stable while the AsX 2 layers exhibit an in-plane ferroelectric instability. All materials display strong excitonic effects and good optical absorption within the infrared-to-visible range. Hence, these monolayers can harvest solar energy and serve in optoelectronics applications. Furthermore, our results indicate that exfoliation of the predicted MX 2 monolayers from their bulk counterparts is experimentally viable.

Materials Science↗
DOE OSTI2020

Materials Data on Bi2S2O by Materials Project

Bi2OS2 crystallizes in the tetragonal P4/nmm space group. The structure is two-dimensional and consists of one BiO sheet oriented in the (0, 0, 1) direction and one BiS2 sheet oriented in the (0, 0, 1) direction. In the BiO sheet, Bi3+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. All Bi–O bond lengths are 2.36 Å. O2- is bonded to four equivalent Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the BiS2 sheet, Bi3+ is bonded to six S2- atoms to form a mixture of distorted edge and corner-sharing BiS6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are a spread of Bi–S bond distances ranging from 2.54–3.41 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to five equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing SBi5 square pyramids. In the second S2- site, S2- is bonded in a distorted single-bond geometry to one Bi3+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1986

Polyimides containing oxyethylene units. Part 4: Polymerization of dianhydrides containing ether linkages

The development of new composite resins for various aerospace applications is attempted. Although it is highly desirable that these polymers be soluble in order to facilitate processing, they must display considerable solvent-resistance in use. A recent approach has involved the synthesis of a new series of polyimides containing flexible linkages. The polymers were prepared by the polymerization of aromatic dianhydrides with diamines containing oxyethylene linkages. For example, the polymerization of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) with 1,2-bis(4-aminophenoxy)ethane (1a) and bis2-(4-aminophenoxy)ethylether (lb), afforded highly crystalline polyimides that were completely insoluble. However, a polyimide that was amorphous and soluble was obtained from the polymerization of BTDA and an isomer of lb, i.e., bis2-(3-aminophenoxy)ethyl ether (4b). In an attempt to obtain a soluble, amorphous polyimide that could be annealed into a crysalline state, block copolymers of 1b and 4b and BTDA were prepared. Copolymers containing less than 20 weight % 1b were soluble in organic solvents. However, these polymers did not crystallize when heated above their Tg's. Copolymers containing higher levels of 1b were semicrystalline and insoluble. The polymerization of the diamines containing oxyethylene linkages with 4,4'-oxydiphthalic anhydride (ODPA) and a new dianhydride, i.e., 4,4'-oxyethyleneoxyethyleneoxydiphthalic anhydride (OEDA) was investigated. It was postulated that the use of these more flexible dianhydrides would result in more processable polyimides.

Harris, F. W.↗
DOE OSTI2021

Out-of-Plane Sulfur Distortions in the Bi4O4S3 Superconductor

The local atomic structure of the non-magnetic layered superconductor Bi4O4S3 was investigated using neutron diffraction and pair density function (PDF) analysis. Although on average, the crystal structure is well ordered, evidence for local, out–of–plane sulfur distortions is provided, which may act as a conduit for charge transfer from the SO4 blocks into the superconducting BiS2 planes. In contrast with LaO1−xFxBiS2, no sulfur distortions were detected in the planes, which indicates that charge density wave fluctuations are not supported in Bi4O4S3.

Philip, Sharon S. (ORCID:000000031055718X)↗