Zr2CoSi2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 6-coordinate geometry to two equivalent Co(1), one Si(1), and five equivalent Si(2) atoms. In the second Zr site, Zr(2) is bonded in a 10-coordinate geometry to four equivalent Co(1), two equivalent Si(2), and four equivalent Si(1) atoms. Co(1) is bonded in a 10-coordinate geometry to two equivalent Zr(1), four equivalent Zr(2), one Si(2), and three equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Zr(1), four equivalent Zr(2), three equivalent Co(1), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Zr(2), five equivalent Zr(1), one Co(1), and one Si(2) atom.
Zr2CoSi2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 6-coordinate geometry to two equivalent Co(1), one Si(1), and five equivalent Si(2) atoms. Both Zr(1)-Co(1) bond lengths are 3.12 Å. The Zr(1)-Si(1) bond length is 2.73 Å. There are a spread of Zr(1)-Si(2) bond distances ranging from 2.79-2.87 Å. In the second Zr site, Zr(2) is bonded in a 10-coordinate geometry to four equivalent Co(1), two equivalent Si(2), and four equivalent Si(1) atoms. There are a spread of Zr(2)-Co(1) bond distances ranging from 2.82-2.97 Å. Both Zr(2)-Si(2) bond lengths are 2.70 Å. There are two shorter (2.84 Å) and two longer (2.85 Å) Zr(2)-Si(1) bond lengths. Co(1) is bonded in a 10-coordinate geometry to two equivalent Zr(1), four equivalent Zr(2), one Si(2), and three equivalent Si(1) atoms. The Co(1)-Si(2) bond length is 2.40 Å. There are two shorter (2.26 Å) and one longer (2.33 Å) Co(1)-Si(1) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Zr(1), four equivalent Zr(2), three equivalent Co(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.52 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Zr(2), five equivalent Zr(1), one Co(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.44 Å.