DOI: 10.17188/1750592
title: Materials Data on Ca(GaS2)2 by Materials Project

description: CaGa2S4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to seven S2- atoms to form distorted CaS7 pentagonal bipyramids that share corners with three equivalent CaS7 pentagonal bipyramids, corners with ten GaS4 tetrahedra, an edgeedge with one CaS7 pentagonal bipyramid, and edges with two GaS4 tetrahedra. There are a spread of Ca–S bond distances ranging from 2.87–3.13 Å. In the second Ca2+ site, Ca2+ is bonded to seven S2- atoms to form distorted CaS7 pentagonal bipyramids that share corners with three equivalent CaS7 pentagonal bipyramids, corners with six GaS4 tetrahedra, edges with two equivalent CaS7 pentagonal bipyramids, and edges with four GaS4 tetrahedra. There are a spread of Ca–S bond distances ranging from 2.89–3.10 Å. There are four inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with four CaS7 pentagonal bipyramids, corners with four GaS4 tetrahedra, and edges with two equivalent CaS7 pentagonal bipyramids. There are a spread of Ga–S bond distances ranging from 2.27–2.34 Å. In the second Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with three CaS7 pentagonal bipyramids, corners with four GaS4 tetrahedra, and edges with two CaS7 pentagonal bipyramids. There are a spread of Ga–S bond distances ranging from 2.27–2.34 Å. In the third Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with six CaS7 pentagonal bipyramids, corners with two GaS4 tetrahedra, and an edgeedge with one GaS4 tetrahedra. There are a spread of Ga–S bond distances ranging from 2.28–2.35 Å. In the fourth Ga3+ site, Ga3+ is bonded to four S2- atoms to form GaS4 tetrahedra that share corners with three equivalent CaS7 pentagonal bipyramids, corners with two GaS4 tetrahedra, edges with two CaS7 pentagonal bipyramids, and an edgeedge with one GaS4 tetrahedra. There are a spread of Ga–S bond distances ranging from 2.25–2.33 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ga3+ atoms. In the second S2- site, S2- is bonded to two Ca2+ and two Ga3+ atoms to form a mixture of distorted corner and edge-sharing SCa2Ga2 trigonal pyramids. In the third S2- site, S2- is bonded to two equivalent Ca2+ and two Ga3+ atoms to form a mixture of distorted corner and edge-sharing SCa2Ga2 tetrahedra. In the fourth S2- site, S2- is bonded to two equivalent Ca2+ and two Ga3+ atoms to form a mixture of distorted corner and edge-sharing SCa2Ga2 tetrahedra. In the fifth S2- site, S2- is bonded in a 3-coordinate geometry to one Ca2+ and two Ga3+ atoms. In the sixth S2- site, S2- is bonded in a 4-coordinate geometry to two Ca2+ and two Ga3+ atoms. In the seventh S2- site, S2- is bonded to two Ca2+ and two Ga3+ atoms to form a mixture of distorted corner and edge-sharing SCa2Ga2 trigonal pyramids. In the eighth S2- site, S2- is bonded in a distorted T-shaped geometry to one Ca2+ and two Ga3+ atoms.