Materials Data on Ca(LuS2)2 by Materials Project

Abstract

Ca(LuS2)2 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 LuS6 octahedra, edges with five LuS6 octahedra, edges with two equivalent CaS7 pentagonal bipyramids, and faces with two equivalent CaS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 14–68°. There are a spread of Ca–S bond distances ranging from 2.86–2.99 Å. There are two inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share corners with three equivalent LuS6 octahedra, corners with four equivalent CaS7 pentagonal bipyramids, edges with six LuS6 octahedra, and an edgeedge with one CaS7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Lu–S bond distances ranging from 2.67–2.77 Å. In the second Lu3+ site, Lu3+ is bonded to six S2- atoms to form LuS6 octahedra that share corners with three equivalent LuS6 octahedra, corners with four equivalent CaS7 pentagonal bipyramids, edges with four LuS6 octahedra, and edges with four equivalent CaS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Lu–S bond distances ranging from 2.66–2.75 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Ca2+ and three Lu3+ atoms to form a mixture of distorted edge and corner-sharing SCa2Lu3 trigonal bipyramids. In the second S2- site, S2- is bonded to two equivalent Ca2+ and three Lu3+ atoms to form SCa2Lu3 square pyramids that share corners with two equivalent SCa3Lu2 square pyramids, corners with two equivalent SCa2Lu3 trigonal bipyramids, edges with five SCa2Lu3 square pyramids, and edges with three equivalent SCa2Lu3 trigonal bipyramids. In the third S2- site, S2- is bonded to three equivalent Ca2+ and two equivalent Lu3+ atoms to form a mixture of edge and corner-sharing SCa3Lu2 square pyramids. In the fourth S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Lu3+ atoms.