Materials Data on IrC2 by Materials Project
IrC2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one IrC2 sheet oriented in the (0, 0, 1) direction. Ir4+ is bonded to six C2- atoms to form distorted IrC6 pentagonal pyramids that share corners with four equivalent IrC6 pentagonal pyramids, corners with three equivalent CIr3C tetrahedra, and edges with four equivalent IrC6 pentagonal pyramids. There are three shorter (2.06 Å) and three longer (2.12 Å) Ir–C bond lengths. There are two inequivalent C2- sites. In the first C2- site, C2- is bonded in a distorted trigonal planar geometry to three equivalent Ir4+ atoms. In the second C2- site, C2- is bonded to three equivalent Ir4+ and one C2- atom to form CIr3C tetrahedra that share corners with three equivalent IrC6 pentagonal pyramids, corners with two equivalent CIr3C tetrahedra, and edges with two equivalent CIr3C tetrahedra. The C–C bond length is 1.40 Å.