Materials Data on V2Cr2GaSe8 by Materials Project
V2Cr2GaSe8 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. V+3.50+ is bonded to six Se2- atoms to form VSe6 octahedra that share corners with three equivalent GaSe4 tetrahedra, edges with two equivalent VSe6 octahedra, and edges with four equivalent CrSe6 octahedra. There are a spread of V–Se bond distances ranging from 2.44–2.67 Å. Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with three equivalent GaSe4 tetrahedra, edges with two equivalent CrSe6 octahedra, and edges with four equivalent VSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.48–2.61 Å. Ga3+ is bonded to four Se2- atoms to form GaSe4 tetrahedra that share corners with six equivalent VSe6 octahedra and corners with six equivalent CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 62–63°. There are two shorter (2.45 Å) and two longer (2.47 Å) Ga–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted T-shaped geometry to one V+3.50+ and two equivalent Cr3+ atoms. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent V+3.50+ and one Cr3+ atom. In the third Se2- site, Se2- is bonded to one V+3.50+, two equivalent Cr3+, and one Ga3+ atom to form a mixture of distorted edge and corner-sharing SeVCr2Ga tetrahedra. In the fourth Se2- site, Se2- is bonded to two equivalent V+3.50+, one Cr3+, and one Ga3+ atom to form a mixture of edge and corner-sharing SeV2CrGa tetrahedra.