CeCoSi3 crystallizes in the tetragonal I-4m2 space group. Ce(1) is bonded in a 16-coordinate geometry to four equivalent Co(1), four equivalent Si(2), and eight equivalent Si(1) atoms. Co(1) is bonded to four equivalent Ce(1), four equivalent Si(1), and four equivalent Si(2) atoms to form distorted CoCe4Si8 cuboctahedra that share corners with four equivalent Si(2)Ce4Co4Si4 cuboctahedra, corners with twelve equivalent Co(1)Ce4Si8 cuboctahedra, edges with two equivalent Si(2)Ce4Co4Si4 cuboctahedra, faces with four equivalent Co(1)Ce4Si8 cuboctahedra, and faces with four equivalent Si(2)Ce4Co4Si4 cuboctahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Ce(1), two equivalent Co(1), one Si(1), and two equivalent Si(2) atoms. In the second Si site, Si(2) is bonded to four equivalent Ce(1), four equivalent Co(1), and four equivalent Si(1) atoms to form distorted SiCe4Co4Si4 cuboctahedra that share corners with four equivalent Co(1)Ce4Si8 cuboctahedra, corners with twelve equivalent Si(2)Ce4Co4Si4 cuboctahedra, edges with two equivalent Co(1)Ce4Si8 cuboctahedra, faces with four equivalent Co(1)Ce4Si8 cuboctahedra, and faces with four equivalent Si(2)Ce4Co4Si4 cuboctahedra.
CeCoSi3 crystallizes in the tetragonal I-4m2 space group. Ce(1) is bonded in a 16-coordinate geometry to four equivalent Co(1), four equivalent Si(2), and eight equivalent Si(1) atoms. All Ce(1)-Co(1) bond lengths are 3.19 Å. All Ce(1)-Si(2) bond lengths are 3.19 Å. All Ce(1)-Si(1) bond lengths are 3.05 Å. Co(1) is bonded to four equivalent Ce(1), four equivalent Si(1), and four equivalent Si(2) atoms to form distorted CoCe4Si8 cuboctahedra that share corners with four equivalent Si(2)Ce4Co4Si4 cuboctahedra, corners with twelve equivalent Co(1)Ce4Si8 cuboctahedra, edges with two equivalent Si(2)Ce4Co4Si4 cuboctahedra, faces with four equivalent Co(1)Ce4Si8 cuboctahedra, and faces with four equivalent Si(2)Ce4Co4Si4 cuboctahedra. All Co(1)-Si(1) bond lengths are 2.37 Å. All Co(1)-Si(2) bond lengths are 2.80 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Ce(1), two equivalent Co(1), one Si(1), and two equivalent Si(2) atoms. The Si(1)-Si(1) bond length is 2.40 Å. Both Si(1)-Si(2) bond lengths are 2.37 Å. In the second Si site, Si(2) is bonded to four equivalent Ce(1), four equivalent Co(1), and four equivalent Si(1) atoms to form distorted SiCe4Co4Si4 cuboctahedra that share corners with four equivalent Co(1)Ce4Si8 cuboctahedra, corners with twelve equivalent Si(2)Ce4Co4Si4 cuboctahedra, edges with two equivalent Co(1)Ce4Si8 cuboctahedra, faces with four equivalent Co(1)Ce4Si8 cuboctahedra, and faces with four equivalent Si(2)Ce4Co4Si4 cuboctahedra.