Si2NCl5 is Indium-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two (cl3 si) n (si cl2)2 n (si cl3) molecules. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent N(1), one Cl(1), and one Cl(2) atom to form SiN2Cl2 tetrahedra that share corners with two equivalent Si(2)NCl3 tetrahedra and  an edgeedge with one Si(1)N2Cl2 tetrahedra. In the second Si site, Si(2) is bonded to one N(1), one Cl(3), one Cl(4), and one Cl(5) atom to form corner-sharing SiNCl3 tetrahedra. N(1) is bonded in a distorted T-shaped geometry to one Si(2) and two equivalent Si(1) atoms. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a single-bond geometry to one Si(1) atom. In the second Cl site, Cl(2) is bonded in a single-bond geometry to one Si(1) atom. In the third Cl site, Cl(3) is bonded in a single-bond geometry to one Si(2) atom. In the fourth Cl site, Cl(4) is bonded in a single-bond geometry to one Si(2) atom. In the fifth Cl site, Cl(5) is bonded in a single-bond geometry to one Si(2) atom.
Si2NCl5 is Indium-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two (cl3 si) n (si cl2)2 n (si cl3) molecules. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent N(1), one Cl(1), and one Cl(2) atom to form SiN2Cl2 tetrahedra that share corners with two equivalent Si(2)NCl3 tetrahedra and  an edgeedge with one Si(1)N2Cl2 tetrahedra. There is one shorter (1.73 Å) and one longer (1.74 Å) Si(1)-N(1) bond length. The Si(1)-Cl(1) bond length is 2.02 Å. The Si(1)-Cl(2) bond length is 2.02 Å. In the second Si site, Si(2) is bonded to one N(1), one Cl(3), one Cl(4), and one Cl(5) atom to form corner-sharing SiNCl3 tetrahedra. The Si(2)-N(1) bond length is 1.70 Å. The Si(2)-Cl(3) bond length is 2.03 Å. The Si(2)-Cl(4) bond length is 2.02 Å. The Si(2)-Cl(5) bond length is 2.03 Å. N(1) is bonded in a distorted T-shaped geometry to one Si(2) and two equivalent Si(1) atoms. There are five inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a single-bond geometry to one Si(1) atom. In the second Cl site, Cl(2) is bonded in a single-bond geometry to one Si(1) atom. In the third Cl site, Cl(3) is bonded in a single-bond geometry to one Si(2) atom. In the fourth Cl site, Cl(4) is bonded in a single-bond geometry to one Si(2) atom. In the fifth Cl site, Cl(5) is bonded in a single-bond geometry to one Si(2) atom.