Materials Data on Mg2Ga2S5 by Materials Project

Abstract

Mg2Ga2S5 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Mg2Ga2S5 sheet oriented in the (0, 0, 1) direction. Mg2+ is bonded to six S2- atoms to form MgS6 octahedra that share corners with three equivalent MgS6 octahedra, corners with three equivalent GaS4 tetrahedra, and edges with nine equivalent MgS6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.54 Å) and three longer (2.64 Å) Mg–S bond lengths. Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with three equivalent MgS6 octahedra and corners with six equivalent GaS4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. There are one shorter (2.20 Å) and three longer (2.38 Å) Ga–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a trigonal non-coplanar geometry to three equivalent Ga3+ atoms. In the second S2- site, S2- is bonded to three equivalent Mg2+ and one Ga3+ atom to form distorted SMg3Ga trigonal pyramids that share corners with three equivalent SMg6 octahedra, corners with six equivalent SMg3Ga trigonal pyramids, and edges with three equivalent SMg6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the third S2- site, S2- is bonded to six equivalent Mg2+ atoms to form SMg6 octahedra that share corners with six equivalent SMg3Ga trigonal pyramids, edges with six equivalent SMg6 octahedra, and edges with six equivalent SMg3Ga trigonal pyramids.