Cr5(SiN3)2 crystallizes in the monoclinic C2/c space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent N(1) and two equivalent N(3) atoms to form distorted CrN4 trigonal pyramids that share corners with four equivalent Si(1)N4 tetrahedra. In the second Cr site, Cr(2) is bonded in a distorted square co-planar geometry to one N(1), one N(3), and two equivalent N(2) atoms. In the third Cr site, Cr(3) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(3) atoms. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted SiN4 tetrahedra that share corners with two equivalent Cr(1)N4 trigonal pyramids and  an edgeedge with one Si(1)N4 tetrahedra. There are three inequivalent N sites. In the first N site, N(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Cr(2) and two equivalent Si(1) atoms. In the second N site, N(3) is bonded to one Cr(1), one Cr(2), two equivalent Cr(3), and one Si(1) atom to form a mixture of distorted corner, edge, and face-sharing NCr4Si square pyramids. In the third N site, N(1) is bonded to one Cr(1), one Cr(2), two equivalent Cr(3), and one Si(1) atom to form a mixture of corner and edge-sharing NCr4Si square pyramids.
Cr5(SiN3)2 crystallizes in the monoclinic C2/c space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent N(1) and two equivalent N(3) atoms to form distorted CrN4 trigonal pyramids that share corners with four equivalent Si(1)N4 tetrahedra. Both Cr(1)-N(1) bond lengths are 1.98 Å. Both Cr(1)-N(3) bond lengths are 2.03 Å. In the second Cr site, Cr(2) is bonded in a distorted square co-planar geometry to one N(1), one N(3), and two equivalent N(2) atoms. The Cr(2)-N(1) bond length is 2.17 Å. The Cr(2)-N(3) bond length is 1.95 Å. There is one shorter (1.96 Å) and one longer (2.04 Å) Cr(2)-N(2) bond length. In the third Cr site, Cr(3) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(3) atoms. There is one shorter (1.99 Å) and one longer (2.00 Å) Cr(3)-N(1) bond length. There is one shorter (2.01 Å) and one longer (2.13 Å) Cr(3)-N(3) bond length. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted SiN4 tetrahedra that share corners with two equivalent Cr(1)N4 trigonal pyramids and  an edgeedge with one Si(1)N4 tetrahedra. The Si(1)-N(1) bond length is 1.76 Å. The Si(1)-N(3) bond length is 1.74 Å. There is one shorter (1.74 Å) and one longer (1.80 Å) Si(1)-N(2) bond length. There are three inequivalent N sites. In the first N site, N(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Cr(2) and two equivalent Si(1) atoms. In the second N site, N(3) is bonded to one Cr(1), one Cr(2), two equivalent Cr(3), and one Si(1) atom to form a mixture of distorted corner, edge, and face-sharing NCr4Si square pyramids. In the third N site, N(1) is bonded to one Cr(1), one Cr(2), two equivalent Cr(3), and one Si(1) atom to form a mixture of corner and edge-sharing NCr4Si square pyramids.