DOE OSTI2020
V3C2 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of two V2C sheets oriented in the (0, 0, 1) direction and two V4C3 sheets oriented in the (0, 0, 1) direction. In each V2C sheet, there are two inequivalent V+2.67+ sites. In the first V+2.67+ site, V+2.67+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All V–C bond lengths are 2.04 Å. In the second V+2.67+ site, V+2.67+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All V–C bond lengths are 2.04 Å. C4- is bonded to six V+2.67+ atoms to form edge-sharing CV6 octahedra. In each V4C3 sheet, there are four inequivalent V+2.67+ sites. In the first V+2.67+ site, V+2.67+ is bonded to six C4- atoms to form a mixture of distorted edge and corner-sharing VC6 pentagonal pyramids. There are three shorter (2.07 Å) and three longer (2.14 Å) V–C bond lengths. In the second V+2.67+ site, V+2.67+ is bonded to six C4- atoms to form a mixture of distorted edge and corner-sharing VC6 pentagonal pyramids. There are three shorter (2.07 Å) and three longer (2.14 Å) V–C bond lengths. In the third V+2.67+ site, V+2.67+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All V–C bond lengths are 1.97 Å. In the fourth V+2.67+ site, V+2.67+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All V–C bond lengths are 1.97 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded to six V+2.67+ atoms to form a mixture of edge, corner, and face-sharing CV6 octahedra. The corner-sharing octahedral tilt angles are 48°. In the second C4- site, C4- is bonded to six V+2.67+ atoms to form a mixture of edge, corner, and face-sharing CV6 octahedra. The corner-sharing octahedral tilt angles are 48°. In the third C4- site, C4- is bonded to six V+2.67+ atoms to form a mixture of edge, corner, and face-sharing CV6 octahedra. The corner-sharing octahedral tilt angles are 48°.