Materials Data on B4C by Materials Project

B4C crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to three equivalent B and one C atom. All B–B bond lengths are 1.79 Å. The B–C bond length is 1.66 Å. In the second B site, B is bonded in a 6-coordinate geometry to six B atoms. There is one shorter (1.72 Å) and two longer (1.83 Å) B–B bond length. There are two inequivalent C sites. In the first C site, C is bonded in a linear geometry to two equivalent C atoms. Both C–C bond lengths are 1.33 Å. In the second C site, C is bonded to three equivalent B and one C atom to form corner-sharing CB3C tetrahedra.