Er8Rh5C12 crystallizes in the monoclinic C2/m space group. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 11-coordinate geometry to two equivalent Rh(1), two equivalent C(3), two equivalent C(4), two equivalent C(6), and three equivalent C(2) atoms. In the second Er site, Er(2) is bonded in a 10-coordinate geometry to two equivalent Rh(1), two equivalent Rh(2), two equivalent Rh(3), two equivalent C(1), and two equivalent C(5) atoms. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to two equivalent C(2), two equivalent C(6), and three equivalent C(3) atoms. In the fourth Er site, Er(4) is bonded in a 8-coordinate geometry to two equivalent Rh(2), two equivalent C(1), two equivalent C(4), and two equivalent C(5) atoms. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 2-coordinate geometry to two equivalent Er(1), two equivalent Er(2), one C(5), and one C(6) atom. In the second Rh site, Rh(2) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(4), one C(4), and one C(6) atom. In the third Rh site, Rh(3) is bonded in a distorted linear geometry to four equivalent Er(2) and two equivalent C(1) atoms. There are six inequivalent C sites. In the first C site, C(4) is bonded in a 4-coordinate geometry to two equivalent Er(1), two equivalent Er(4), one Rh(2), and one C(3) atom. In the second C site, C(5) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(4), one Rh(1), and one C(1) atom. In the third C site, C(6) is bonded in a 7-coordinate geometry to two equivalent Er(1), two equivalent Er(3), one Rh(1), one Rh(2), and one C(2) atom. In the fourth C site, C(1) is bonded to two equivalent Er(2), two equivalent Er(4), one Rh(3), and one C(5) atom to form a mixture of distorted edge and corner-sharing CEr4RhC octahedra. The corner-sharing octahedra are not tilted. In the fifth C site, C(2) is bonded to two equivalent Er(3), three equivalent Er(1), and one C(6) atom to form a mixture of distorted edge and corner-sharing CEr5C octahedra. The corner-sharing octahedral tilt angles range from 6-14°. In the sixth C site, C(3) is bonded to two equivalent Er(1), three equivalent Er(3), and one C(4) atom to form a mixture of edge and corner-sharing CEr5C octahedra. The corner-sharing octahedral tilt angles range from 6-14°.
Er8Rh5C12 crystallizes in the monoclinic C2/m space group. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 11-coordinate geometry to two equivalent Rh(1), two equivalent C(3), two equivalent C(4), two equivalent C(6), and three equivalent C(2) atoms. Both Er(1)-Rh(1) bond lengths are 3.12 Å. Both Er(1)-C(3) bond lengths are 2.58 Å. Both Er(1)-C(4) bond lengths are 2.91 Å. Both Er(1)-C(6) bond lengths are 2.72 Å. There is one shorter (2.33 Å) and two longer (2.58 Å) Er(1)-C(2) bond lengths. In the second Er site, Er(2) is bonded in a 10-coordinate geometry to two equivalent Rh(1), two equivalent Rh(2), two equivalent Rh(3), two equivalent C(1), and two equivalent C(5) atoms. Both Er(2)-Rh(1) bond lengths are 2.82 Å. Both Er(2)-Rh(2) bond lengths are 2.94 Å. Both Er(2)-Rh(3) bond lengths are 3.02 Å. Both Er(2)-C(1) bond lengths are 2.62 Å. Both Er(2)-C(5) bond lengths are 2.92 Å. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to two equivalent C(2), two equivalent C(6), and three equivalent C(3) atoms. Both Er(3)-C(2) bond lengths are 2.54 Å. Both Er(3)-C(6) bond lengths are 2.72 Å. There is one shorter (2.39 Å) and two longer (2.53 Å) Er(3)-C(3) bond lengths. In the fourth Er site, Er(4) is bonded in a 8-coordinate geometry to two equivalent Rh(2), two equivalent C(1), two equivalent C(4), and two equivalent C(5) atoms. Both Er(4)-Rh(2) bond lengths are 2.89 Å. Both Er(4)-C(1) bond lengths are 2.55 Å. Both Er(4)-C(4) bond lengths are 2.62 Å. Both Er(4)-C(5) bond lengths are 2.56 Å. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 2-coordinate geometry to two equivalent Er(1), two equivalent Er(2), one C(5), and one C(6) atom. The Rh(1)-C(5) bond length is 2.00 Å. The Rh(1)-C(6) bond length is 2.02 Å. In the second Rh site, Rh(2) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(4), one C(4), and one C(6) atom. The Rh(2)-C(4) bond length is 2.30 Å. The Rh(2)-C(6) bond length is 2.10 Å. In the third Rh site, Rh(3) is bonded in a distorted linear geometry to four equivalent Er(2) and two equivalent C(1) atoms. Both Rh(3)-C(1) bond lengths are 1.96 Å. There are six inequivalent C sites. In the first C site, C(4) is bonded in a 4-coordinate geometry to two equivalent Er(1), two equivalent Er(4), one Rh(2), and one C(3) atom. The C(4)-C(3) bond length is 1.36 Å. In the second C site, C(5) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(4), one Rh(1), and one C(1) atom. The C(5)-C(1) bond length is 1.30 Å. In the third C site, C(6) is bonded in a 7-coordinate geometry to two equivalent Er(1), two equivalent Er(3), one Rh(1), one Rh(2), and one C(2) atom. The C(6)-C(2) bond length is 1.34 Å. In the fourth C site, C(1) is bonded to two equivalent Er(2), two equivalent Er(4), one Rh(3), and one C(5) atom to form a mixture of distorted edge and corner-sharing CEr4RhC octahedra. The corner-sharing octahedra are not tilted. In the fifth C site, C(2) is bonded to two equivalent Er(3), three equivalent Er(1), and one C(6) atom to form a mixture of distorted edge and corner-sharing CEr5C octahedra. The corner-sharing octahedral tilt angles range from 6-14°. In the sixth C site, C(3) is bonded to two equivalent Er(1), three equivalent Er(3), and one C(4) atom to form a mixture of edge and corner-sharing CEr5C octahedra. The corner-sharing octahedral tilt angles range from 6-14°.