DOI: 10.17188/1717667
title: Materials Data on K2Bi8Se13 by Materials Project

description: 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°.