Materials Data on CaSO4 by Materials Project

Abstract

CaSO4 is Zircon-like structured and crystallizes in the hexagonal P6_222 space group. The structure is three-dimensional. Ca2+ is bonded to eight equivalent O2- atoms to form distorted CaO8 hexagonal bipyramids that share corners with four equivalent SO4 tetrahedra, edges with four equivalent CaO8 hexagonal bipyramids, and edges with two equivalent SO4 tetrahedra. There are four shorter (2.41 Å) and four longer (2.57 Å) Ca–O bond lengths. S6+ is bonded to four equivalent O2- atoms to form SO4 tetrahedra that share corners with four equivalent CaO8 hexagonal bipyramids and edges with two equivalent CaO8 hexagonal bipyramids. All S–O bond lengths are 1.49 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one S6+ atom.