Er7Co6Sn23 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 12-coordinate geometry to two equivalent Co(1), one Sn(4), one Sn(5), two equivalent Sn(1), two equivalent Sn(3), and four equivalent Sn(2) atoms. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Sn(1), and six equivalent Sn(3) atoms. Co(1) is bonded in a 9-coordinate geometry to one Er(2), two equivalent Er(1), one Sn(2), one Sn(5), two equivalent Sn(1), and two equivalent Sn(3) atoms. There are six inequivalent Sn sites. In the first Sn site, Sn(5) is bonded in a 7-coordinate geometry to three equivalent Er(1), three equivalent Co(1), and one Sn(4) atom. In the second Sn site, Sn(6) is bonded in a 6-coordinate geometry to six equivalent Sn(1) atoms. In the third Sn site, Sn(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent Co(1), one Sn(2), and one Sn(6) atom. In the fourth Sn site, Sn(2) is bonded in a 5-coordinate geometry to four equivalent Er(1), one Co(1), and one Sn(1) atom. In the fifth Sn site, Sn(3) is bonded in a 2-coordinate geometry to one Er(2), two equivalent Er(1), and two equivalent Co(1) atoms. In the sixth Sn site, Sn(4) is bonded in a 3-coordinate geometry to three equivalent Er(1) and one Sn(5) atom.
Er7Co6Sn23 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 12-coordinate geometry to two equivalent Co(1), one Sn(4), one Sn(5), two equivalent Sn(1), two equivalent Sn(3), and four equivalent Sn(2) atoms. Both Er(1)-Co(1) bond lengths are 3.15 Å. The Er(1)-Sn(4) bond length is 3.06 Å. The Er(1)-Sn(5) bond length is 3.37 Å. Both Er(1)-Sn(1) bond lengths are 3.20 Å. Both Er(1)-Sn(3) bond lengths are 3.37 Å. There are two shorter (3.08 Å) and two longer (3.24 Å) Er(1)-Sn(2) bond lengths. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Sn(1), and six equivalent Sn(3) atoms. All Er(2)-Co(1) bond lengths are 3.40 Å. All Er(2)-Sn(1) bond lengths are 3.34 Å. All Er(2)-Sn(3) bond lengths are 3.34 Å. Co(1) is bonded in a 9-coordinate geometry to one Er(2), two equivalent Er(1), one Sn(2), one Sn(5), two equivalent Sn(1), and two equivalent Sn(3) atoms. The Co(1)-Sn(2) bond length is 2.65 Å. The Co(1)-Sn(5) bond length is 2.77 Å. Both Co(1)-Sn(1) bond lengths are 2.60 Å. Both Co(1)-Sn(3) bond lengths are 2.56 Å. There are six inequivalent Sn sites. In the first Sn site, Sn(5) is bonded in a 7-coordinate geometry to three equivalent Er(1), three equivalent Co(1), and one Sn(4) atom. The Sn(5)-Sn(4) bond length is 2.91 Å. In the second Sn site, Sn(6) is bonded in a 6-coordinate geometry to six equivalent Sn(1) atoms. All Sn(6)-Sn(1) bond lengths are 2.95 Å. In the third Sn site, Sn(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent Co(1), one Sn(2), and one Sn(6) atom. The Sn(1)-Sn(2) bond length is 3.17 Å. In the fourth Sn site, Sn(2) is bonded in a 5-coordinate geometry to four equivalent Er(1), one Co(1), and one Sn(1) atom. In the fifth Sn site, Sn(3) is bonded in a 2-coordinate geometry to one Er(2), two equivalent Er(1), and two equivalent Co(1) atoms. In the sixth Sn site, Sn(4) is bonded in a 3-coordinate geometry to three equivalent Er(1) and one Sn(5) atom.