DOE OSTI2020
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.