ErCoC2 crystallizes in the orthorhombic Amm2 space group. Er(1) is bonded in a 8-coordinate geometry to eight equivalent C(1) atoms. Co(1) is bonded in a 4-coordinate geometry to four equivalent C(1) atoms. C(1) is bonded in a 7-coordinate geometry to four equivalent Er(1), two equivalent Co(1), and one C(1) atom.
ErCoC2 crystallizes in the orthorhombic Amm2 space group. Er(1) is bonded in a 8-coordinate geometry to eight equivalent C(1) atoms. There are four shorter (2.60 Å) and four longer (2.62 Å) Er(1)-C(1) bond lengths. Co(1) is bonded in a 4-coordinate geometry to four equivalent C(1) atoms. There are two shorter (1.91 Å) and two longer (1.96 Å) Co(1)-C(1) bond lengths. C(1) is bonded in a 7-coordinate geometry to four equivalent Er(1), two equivalent Co(1), and one C(1) atom. The C(1)-C(1) bond length is 1.38 Å.