Materials Data on V2NiSe4 by Materials Project
V2NiSe4 is MAX Phase-like structured and crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one V2NiSe4 sheet oriented in the (0, 0, 1) direction. V3+ is bonded to six Se2- atoms to form VSe6 octahedra that share corners with six equivalent NiSe6 octahedra, edges with six equivalent VSe6 octahedra, and a faceface with one NiSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of V–Se bond distances ranging from 2.50–2.60 Å. Ni2+ is bonded to six equivalent Se2- atoms to form NiSe6 octahedra that share corners with twelve equivalent VSe6 octahedra, edges with six equivalent NiSe6 octahedra, and faces with two equivalent VSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. All Ni–Se bond lengths are 2.48 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted T-shaped geometry to three equivalent V3+ atoms. In the second Se2- site, Se2- is bonded to three equivalent V3+ and three equivalent Ni2+ atoms to form a mixture of distorted corner and edge-sharing SeV3Ni3 pentagonal pyramids.