Materials Data on Ca(YS2)2 by Materials Project

Abstract

CaY2S4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded to seven S2- atoms to form distorted CaS7 pentagonal bipyramids that share corners with eight YS6 octahedra, edges with five YS6 octahedra, edges with two equivalent CaS7 pentagonal bipyramids, and faces with two equivalent CaS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–68°. There are a spread of Ca–S bond distances ranging from 2.88–3.06 Å. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, corners with four equivalent CaS7 pentagonal bipyramids, edges with six YS6 octahedra, and an edgeedge with one CaS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Y–S bond distances ranging from 2.72–2.82 Å. In the second Y3+ site, Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, corners with four equivalent CaS7 pentagonal bipyramids, edges with four YS6 octahedra, and edges with four equivalent CaS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Y–S bond distances ranging from 2.73–2.79 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Ca2+ and two equivalent Y3+ atoms to form a mixture of corner and edge-sharing SCa3Y2 square pyramids. In the second S2- site, S2- is bonded to two equivalent Ca2+ and three Y3+ atoms to form SCa2Y3 square pyramids that share corners with two equivalent SCa3Y2 square pyramids, corners with two equivalent SCa2Y3 trigonal bipyramids, edges with five SCa2Y3 square pyramids, and edges with three equivalent SCa2Y3 trigonal bipyramids. In the third S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Y3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Ca2+ and three Y3+ atoms to form a mixture of distorted corner and edge-sharing SCa2Y3 trigonal bipyramids.