Materials Data on VCr3GaSe8 by Materials Project
VCr3GaSe8 crystallizes in the trigonal R3m space group. The structure is three-dimensional. V5+ is bonded to six Se2- atoms to form VSe6 octahedra that share corners with three equivalent GaSe4 tetrahedra and edges with six equivalent CrSe6 octahedra. There are three shorter (2.43 Å) and three longer (2.69 Å) V–Se bond lengths. Cr+2.67+ is bonded to six Se2- atoms to form CrSe6 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 Cr–Se bond distances ranging from 2.48–2.60 Å. Ga3+ is bonded to four Se2- atoms to form GaSe4 tetrahedra that share corners with three equivalent VSe6 octahedra and corners with nine equivalent CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 61–62°. There are one shorter (2.45 Å) and three longer (2.47 Å) Ga–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Cr+2.67+ and one Ga3+ atom to form a mixture of distorted corner and edge-sharing SeCr3Ga tetrahedra. In the second Se2- site, Se2- is bonded to one V5+, two equivalent Cr+2.67+, and one Ga3+ atom to form a mixture of distorted corner and edge-sharing SeVCr2Ga tetrahedra. In the third Se2- site, Se2- is bonded in a distorted T-shaped geometry to three equivalent Cr+2.67+ atoms. In the fourth Se2- site, Se2- is bonded in a distorted T-shaped geometry to one V5+ and two equivalent Cr+2.67+ atoms.