ErCoC crystallizes in the tetragonal P4_2/mmc space group. Er(1) is bonded in a 4-coordinate geometry to four equivalent C(1) atoms. Co(1) is bonded in a linear geometry to two equivalent C(1) atoms. C(1) is bonded to four equivalent Er(1) and two equivalent Co(1) atoms to form a mixture of corner and edge-sharing CEr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°.
ErCoC crystallizes in the tetragonal P4_2/mmc space group. Er(1) is bonded in a 4-coordinate geometry to four equivalent C(1) atoms. All Er(1)-C(1) bond lengths are 2.47 Å. Co(1) is bonded in a linear geometry to two equivalent C(1) atoms. Both Co(1)-C(1) bond lengths are 1.80 Å. C(1) is bonded to four equivalent Er(1) and two equivalent Co(1) atoms to form a mixture of corner and edge-sharing CEr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°.