Sc2CoSi2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 6-coordinate geometry to two equivalent Co(1), one Si(2), and five equivalent Si(1) atoms. In the second Sc site, Sc(2) is bonded in a 10-coordinate geometry to four equivalent Co(1), two equivalent Si(1), and five equivalent Si(2) atoms. Co(1) is bonded in a 10-coordinate geometry to two equivalent Sc(1), four equivalent Sc(2), one Si(1), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Sc(2), five equivalent Sc(1), one Co(1), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Sc(1), five equivalent Sc(2), three equivalent Co(1), and one Si(2) atom.
Sc2CoSi2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 6-coordinate geometry to two equivalent Co(1), one Si(2), and five equivalent Si(1) atoms. Both Sc(1)-Co(1) bond lengths are 3.09 Å. The Sc(1)-Si(2) bond length is 2.69 Å. There are four shorter (2.82 Å) and one longer (2.92 Å) Sc(1)-Si(1) bond length. In the second Sc site, Sc(2) is bonded in a 10-coordinate geometry to four equivalent Co(1), two equivalent Si(1), and five equivalent Si(2) atoms. There are a spread of Sc(2)-Co(1) bond distances ranging from 2.78-2.95 Å. Both Sc(2)-Si(1) bond lengths are 2.71 Å. There are a spread of Sc(2)-Si(2) bond distances ranging from 2.81-3.13 Å. Co(1) is bonded in a 10-coordinate geometry to two equivalent Sc(1), four equivalent Sc(2), one Si(1), and three equivalent Si(2) atoms. The Co(1)-Si(1) bond length is 2.39 Å. There are two shorter (2.26 Å) and one longer (2.31 Å) Co(1)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Sc(2), five equivalent Sc(1), one Co(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.48 Å. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to one Sc(1), five equivalent Sc(2), three equivalent Co(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.51 Å.