Materials Data on Cr(GaS2)2 by Materials Project

Abstract

Cr(GaS2)2 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of one Cr(GaS2)2 sheet oriented in the (0, 0, 1) direction. Cr2+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with six GaS4 tetrahedra and edges with six equivalent CrS6 octahedra. There are four shorter (2.47 Å) and two longer (2.49 Å) Cr–S bond lengths. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with three equivalent CrS6 octahedra and corners with six equivalent GaS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–60°. There are a spread of Ga–S bond distances ranging from 2.29–2.36 Å. In the second Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with three equivalent CrS6 octahedra and corners with six equivalent GaS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–60°. There are a spread of Ga–S bond distances ranging from 2.29–2.36 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Cr2+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing SCr3Ga trigonal pyramids. In the second S2- site, S2- is bonded to three equivalent Cr2+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing SCr3Ga trigonal pyramids. In the third S2- site, S2- is bonded in a trigonal non-coplanar geometry to three equivalent Ga3+ atoms. In the fourth S2- site, S2- is bonded in a trigonal non-coplanar geometry to three equivalent Ga3+ atoms.