GaSi3C3N is Stannite-like structured and crystallizes in the monoclinic Pm space group. Ga(1) is bonded to one C(1), one C(2), and two equivalent N(1) atoms to form GaC2N2 tetrahedra that share corners with two equivalent Ga(1)C2N2 tetrahedra, corners with two equivalent Si(3)C4 tetrahedra, corners with four equivalent Si(1)C3N tetrahedra, and corners with four equivalent Si(2)C3N tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one C(3), two equivalent C(1), and one N(1) atom to form SiC3N tetrahedra that share corners with two equivalent Si(1)C3N tetrahedra, corners with two equivalent Si(2)C3N tetrahedra, corners with four equivalent Ga(1)C2N2 tetrahedra, and corners with four equivalent Si(3)C4 tetrahedra. In the second Si site, Si(2) is bonded to one C(3), two equivalent C(2), and one N(1) atom to form SiC3N tetrahedra that share corners with two equivalent Si(1)C3N tetrahedra, corners with two equivalent Si(2)C3N tetrahedra, corners with four equivalent Ga(1)C2N2 tetrahedra, and corners with four equivalent Si(3)C4 tetrahedra. In the third Si site, Si(3) is bonded to one C(1), one C(2), and two equivalent C(3) atoms to form SiC4 tetrahedra that share corners with two equivalent Ga(1)C2N2 tetrahedra, corners with two equivalent Si(3)C4 tetrahedra, corners with four equivalent Si(1)C3N tetrahedra, and corners with four equivalent Si(2)C3N tetrahedra. There are three inequivalent C sites. In the first C site, C(1) is bonded to one Ga(1), one Si(3), and two equivalent Si(1) atoms to form CGaSi3 tetrahedra that share corners with two equivalent C(1)GaSi3 tetrahedra, corners with two equivalent C(2)GaSi3 tetrahedra, corners with four equivalent C(3)Si4 tetrahedra, and corners with four equivalent N(1)Ga2Si2 tetrahedra. In the second C site, C(2) is bonded to one Ga(1), one Si(3), and two equivalent Si(2) atoms to form CGaSi3 tetrahedra that share corners with two equivalent C(1)GaSi3 tetrahedra, corners with two equivalent C(2)GaSi3 tetrahedra, corners with four equivalent C(3)Si4 tetrahedra, and corners with four equivalent N(1)Ga2Si2 tetrahedra. In the third C site, C(3) is bonded to one Si(1), one Si(2), and two equivalent Si(3) atoms to form CSi4 tetrahedra that share corners with two equivalent C(3)Si4 tetrahedra, corners with two equivalent N(1)Ga2Si2 tetrahedra, corners with four equivalent C(1)GaSi3 tetrahedra, and corners with four equivalent C(2)GaSi3 tetrahedra. N(1) is bonded to two equivalent Ga(1), one Si(1), and one Si(2) atom to form NGa2Si2 tetrahedra that share corners with two equivalent C(3)Si4 tetrahedra, corners with two equivalent N(1)Ga2Si2 tetrahedra, corners with four equivalent C(1)GaSi3 tetrahedra, and corners with four equivalent C(2)GaSi3 tetrahedra.
GaSi3C3N is Stannite-like structured and crystallizes in the monoclinic Pm space group. Ga(1) is bonded to one C(1), one C(2), and two equivalent N(1) atoms to form GaC2N2 tetrahedra that share corners with two equivalent Ga(1)C2N2 tetrahedra, corners with two equivalent Si(3)C4 tetrahedra, corners with four equivalent Si(1)C3N tetrahedra, and corners with four equivalent Si(2)C3N tetrahedra. The Ga(1)-C(1) bond length is 2.02 Å. The Ga(1)-C(2) bond length is 2.00 Å. Both Ga(1)-N(1) bond lengths are 2.00 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one C(3), two equivalent C(1), and one N(1) atom to form SiC3N tetrahedra that share corners with two equivalent Si(1)C3N tetrahedra, corners with two equivalent Si(2)C3N tetrahedra, corners with four equivalent Ga(1)C2N2 tetrahedra, and corners with four equivalent Si(3)C4 tetrahedra. The Si(1)-C(3) bond length is 1.90 Å. Both Si(1)-C(1) bond lengths are 1.88 Å. The Si(1)-N(1) bond length is 1.83 Å. In the second Si site, Si(2) is bonded to one C(3), two equivalent C(2), and one N(1) atom to form SiC3N tetrahedra that share corners with two equivalent Si(1)C3N tetrahedra, corners with two equivalent Si(2)C3N tetrahedra, corners with four equivalent Ga(1)C2N2 tetrahedra, and corners with four equivalent Si(3)C4 tetrahedra. The Si(2)-C(3) bond length is 1.91 Å. Both Si(2)-C(2) bond lengths are 1.87 Å. The Si(2)-N(1) bond length is 1.81 Å. In the third Si site, Si(3) is bonded to one C(1), one C(2), and two equivalent C(3) atoms to form SiC4 tetrahedra that share corners with two equivalent Ga(1)C2N2 tetrahedra, corners with two equivalent Si(3)C4 tetrahedra, corners with four equivalent Si(1)C3N tetrahedra, and corners with four equivalent Si(2)C3N tetrahedra. The Si(3)-C(1) bond length is 1.90 Å. The Si(3)-C(2) bond length is 1.89 Å. Both Si(3)-C(3) bond lengths are 1.91 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded to one Ga(1), one Si(3), and two equivalent Si(1) atoms to form CGaSi3 tetrahedra that share corners with two equivalent C(1)GaSi3 tetrahedra, corners with two equivalent C(2)GaSi3 tetrahedra, corners with four equivalent C(3)Si4 tetrahedra, and corners with four equivalent N(1)Ga2Si2 tetrahedra. In the second C site, C(2) is bonded to one Ga(1), one Si(3), and two equivalent Si(2) atoms to form CGaSi3 tetrahedra that share corners with two equivalent C(1)GaSi3 tetrahedra, corners with two equivalent C(2)GaSi3 tetrahedra, corners with four equivalent C(3)Si4 tetrahedra, and corners with four equivalent N(1)Ga2Si2 tetrahedra. In the third C site, C(3) is bonded to one Si(1), one Si(2), and two equivalent Si(3) atoms to form CSi4 tetrahedra that share corners with two equivalent C(3)Si4 tetrahedra, corners with two equivalent N(1)Ga2Si2 tetrahedra, corners with four equivalent C(1)GaSi3 tetrahedra, and corners with four equivalent C(2)GaSi3 tetrahedra. N(1) is bonded to two equivalent Ga(1), one Si(1), and one Si(2) atom to form NGa2Si2 tetrahedra that share corners with two equivalent C(3)Si4 tetrahedra, corners with two equivalent N(1)Ga2Si2 tetrahedra, corners with four equivalent C(1)GaSi3 tetrahedra, and corners with four equivalent C(2)GaSi3 tetrahedra.