Tm2Co7B3 crystallizes in the hexagonal P6/mmm space group. There are three inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to two equivalent Tm(3), twelve equivalent Co(3), and six equivalent B(1) atoms. In the third Tm site, Tm(3) is bonded in a 18-coordinate geometry to one Tm(2), six equivalent Co(2), six equivalent Co(3), and six equivalent B(2) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to three equivalent Tm(1) and six equivalent Co(2) atoms. In the second Co site, Co(2) is bonded in a distorted L-shaped geometry to two equivalent Tm(3), two equivalent Co(1), and two equivalent B(2) atoms. In the third Co site, Co(3) is bonded in a distorted square co-planar geometry to two equivalent Tm(2), two equivalent Tm(3), two equivalent B(1), and two equivalent B(2) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 6-coordinate geometry to three equivalent Tm(2) and six equivalent Co(3) atoms. In the second B site, B(2) is bonded in a 6-coordinate geometry to three equivalent Tm(3), three equivalent Co(2), and three equivalent Co(3) atoms.
Tm2Co7B3 crystallizes in the hexagonal P6/mmm space group. There are three inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. All Tm(1)-Co(1) bond lengths are 2.88 Å. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to two equivalent Tm(3), twelve equivalent Co(3), and six equivalent B(1) atoms. Both Tm(2)-Tm(3) bond lengths are 3.07 Å. All Tm(2)-Co(3) bond lengths are 2.90 Å. All Tm(2)-B(1) bond lengths are 2.88 Å. In the third Tm site, Tm(3) is bonded in a 18-coordinate geometry to one Tm(2), six equivalent Co(2), six equivalent Co(3), and six equivalent B(2) atoms. All Tm(3)-Co(2) bond lengths are 2.85 Å. All Tm(3)-Co(3) bond lengths are 2.96 Å. All Tm(3)-B(2) bond lengths are 2.89 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to three equivalent Tm(1) and six equivalent Co(2) atoms. All Co(1)-Co(2) bond lengths are 2.45 Å. In the second Co site, Co(2) is bonded in a distorted L-shaped geometry to two equivalent Tm(3), two equivalent Co(1), and two equivalent B(2) atoms. Both Co(2)-B(2) bond lengths are 2.05 Å. In the third Co site, Co(3) is bonded in a distorted square co-planar geometry to two equivalent Tm(2), two equivalent Tm(3), two equivalent B(1), and two equivalent B(2) atoms. Both Co(3)-B(1) bond lengths are 2.07 Å. Both Co(3)-B(2) bond lengths are 2.08 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 6-coordinate geometry to three equivalent Tm(2) and six equivalent Co(3) atoms. In the second B site, B(2) is bonded in a 6-coordinate geometry to three equivalent Tm(3), three equivalent Co(2), and three equivalent Co(3) atoms.