ErNiC2 crystallizes in the orthorhombic Amm2 space group. Er(1) is bonded in a 8-coordinate geometry to eight equivalent C(1) atoms. Ni(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 Ni(1), and one C(1) atom.
ErNiC2 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 (2.63 Å) Er(1)-C(1) bond lengths. Ni(1) is bonded in a 4-coordinate geometry to four equivalent C(1) atoms. There are two shorter (1.92 Å) and two longer (1.97 Å) Ni(1)-C(1) bond lengths. C(1) is bonded in a 7-coordinate geometry to four equivalent Er(1), two equivalent Ni(1), and one C(1) atom. The C(1)-C(1) bond length is 1.37 Å.