DOI: 10.17188/1275674
title: Materials Data on K12In2Se9 by Materials Project

description: K12In2Se9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are twelve inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.24–4.00 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.39–3.98 Å. In the third K1+ site, K1+ is bonded to five Se2- atoms to form distorted KSe5 square pyramids that share corners with three KSe6 octahedra, a cornercorner with one KSe5 square pyramid, a cornercorner with one InSe4 tetrahedra, corners with three equivalent KSe5 trigonal bipyramids, an edgeedge with one KSe6 octahedra, edges with two InSe4 tetrahedra, a faceface with one KSe5 square pyramid, and a faceface with one KSe5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 40–53°. There are a spread of K–Se bond distances ranging from 3.30–3.43 Å. In the fourth K1+ site, K1+ is bonded to five Se2- atoms to form distorted KSe5 trigonal bipyramids that share a cornercorner with one KSe6 octahedra, a cornercorner with one KSe5 square pyramid, corners with four InSe4 tetrahedra, corners with two equivalent KSe5 trigonal bipyramids, an edgeedge with one KSe5 square pyramid, an edgeedge with one KSe5 trigonal bipyramid, faces with two KSe6 octahedra, and a faceface with one KSe5 square pyramid. The corner-sharing octahedral tilt angles are 50°. There are a spread of K–Se bond distances ranging from 3.15–3.60 Å. In the fifth K1+ site, K1+ is bonded in a 3-coordinate geometry to five Se2- atoms. There are a spread of K–Se bond distances ranging from 3.19–4.03 Å. In the sixth K1+ site, K1+ is bonded to five Se2- atoms to form distorted KSe5 trigonal bipyramids that share a cornercorner with one KSe6 octahedra, corners with four KSe5 square pyramids, corners with two equivalent KSe5 trigonal bipyramids, edges with two KSe6 octahedra, an edgeedge with one KSe5 square pyramid, edges with two InSe4 tetrahedra, an edgeedge with one KSe5 trigonal bipyramid, and a faceface with one KSe6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of K–Se bond distances ranging from 3.29–3.48 Å. In the seventh K1+ site, K1+ is bonded to six Se2- atoms to form distorted KSe6 octahedra that share a cornercorner with one KSe6 octahedra, corners with four KSe5 square pyramids, corners with two equivalent InSe4 tetrahedra, a cornercorner with one KSe5 trigonal bipyramid, an edgeedge with one KSe5 square pyramid, an edgeedge with one KSe5 trigonal bipyramid, a faceface with one KSe6 octahedra, a faceface with one InSe4 tetrahedra, and faces with two KSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 58°. There are a spread of K–Se bond distances ranging from 3.46–3.60 Å. In the eighth K1+ site, K1+ is bonded to six Se2- atoms to form distorted KSe6 octahedra that share a cornercorner with one KSe6 octahedra, corners with four KSe5 square pyramids, corners with five InSe4 tetrahedra, a cornercorner with one KSe5 trigonal bipyramid, an edgeedge with one KSe5 trigonal bipyramid, a faceface with one KSe6 octahedra, and a faceface with one KSe5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 58°. There are a spread of K–Se bond distances ranging from 3.30–3.88 Å. In the ninth K1+ site, K1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.24–3.90 Å. In the tenth K1+ site, K1+ is bonded to five Se2- atoms to form distorted KSe5 square pyramids that share corners with five KSe6 octahedra, a cornercorner with one KSe5 square pyramid, corners with two KSe5 trigonal bipyramids, edges with two InSe4 tetrahedra, edges with two KSe5 trigonal bipyramids, and a faceface with one KSe5 square pyramid. The corner-sharing octahedra tilt angles range from 26–52°. There are a spread of K–Se bond distances ranging from 3.40–3.78 Å. In the eleventh K1+ site, K1+ is bonded in a distorted see-saw-like geometry to four Se2- atoms. There are a spread of K–Se bond distances ranging from 3.31–3.55 Å. In the twelfth K1+ site, K1+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of K–Se bond distances ranging from 3.28–3.53 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with three equivalent KSe6 octahedra, a cornercorner with one KSe5 trigonal bipyramid, edges with two KSe5 square pyramids, an edgeedge with one KSe5 trigonal bipyramid, and a faceface with one KSe6 octahedra. The corner-sharing octahedra tilt angles range from 13–48°. There are a spread of In–Se bond distances ranging from 2.62–2.65 Å. In the second In3+ site, In3+ is bonded to four Se2- atoms to form InSe4 tetrahedra that share corners with four KSe6 octahedra, a cornercorner with one KSe5 square pyramid, corners with three equivalent KSe5 trigonal bipyramids, edges with two KSe5 square pyramids, and an edgeedge with one KSe5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 28–70°. There are a spread of In–Se bond distances ranging from 2.62–2.67 Å. There are nine inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to seven K1+ and one In3+ atom. In the second Se2- site, Se2- is bonded in a 7-coordinate geometry to six K1+ and one In3+ atom. In the third Se2- site, Se2- is bonded in a 8-coordinate geometry to seven K1+ and one In3+ atom. In the fourth Se2- site, Se2- is bonded in a 8-coordinate geometry to seven K1+ and one In3+ atom. In the fifth Se2- site, Se2- is bonded in a 1-coordinate geometry to seven K1+ and one In3+ atom. In the sixth Se2- site, Se2- is bonded in a 1-coordinate geometry to seven K1+ and one In3+ atom. In the seventh Se2- site, Se2- is bonded in a 8-coordinate geometry to eight K1+ atoms. In the eighth Se2- site, Se2- is bonded in a 8-coordinate geometry to seven K1+ and one In3+ atom. In the ninth Se2- site, Se2- is bonded in a 1-coordinate geometry to eight K1+ and one In3+ atom.