MgB2C2 crystallizes in the orthorhombic Pnnm space group. Mg(1) is bonded to six equivalent B(1) and six equivalent C(1) atoms to form a mixture of distorted edge and face-sharing MgB6C6 cuboctahedra. B(1) is bonded in a trigonal planar geometry to three equivalent Mg(1) and three equivalent C(1) atoms. C(1) is bonded in a distorted trigonal planar geometry to three equivalent Mg(1) and three equivalent B(1) atoms.
MgB2C2 crystallizes in the orthorhombic Pnnm space group. Mg(1) is bonded to six equivalent B(1) and six equivalent C(1) atoms to form a mixture of distorted edge and face-sharing MgB6C6 cuboctahedra. There are two shorter (2.42 Å) and four longer (2.44 Å) Mg(1)-B(1) bond lengths. There are four shorter (2.32 Å) and two longer (2.40 Å) Mg(1)-C(1) bond lengths. B(1) is bonded in a trigonal planar geometry to three equivalent Mg(1) and three equivalent C(1) atoms. There is one shorter (1.57 Å) and two longer (1.59 Å) B(1)-C(1) bond lengths. C(1) is bonded in a distorted trigonal planar geometry to three equivalent Mg(1) and three equivalent B(1) atoms.