Nb4GaSe8 crystallizes in the cubic F-43m space group. Nb(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form distorted NbSe6 octahedra that share corners with three equivalent Ga(1)Se4 tetrahedra and edges with six equivalent Nb(1)Se6 octahedra. Ga(1) is bonded to four equivalent Se(1) atoms to form GaSe4 tetrahedra that share corners with twelve equivalent Nb(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Nb(1) and one Ga(1) atom to form a mixture of corner and edge-sharing SeNb3Ga tetrahedra. In the second Se site, Se(2) is bonded in a 3-coordinate geometry to three equivalent Nb(1) atoms.
Nb4GaSe8 crystallizes in the cubic F-43m space group. Nb(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form distorted NbSe6 octahedra that share corners with three equivalent Ga(1)Se4 tetrahedra and edges with six equivalent Nb(1)Se6 octahedra. All Nb(1)-Se(1) bond lengths are 2.81 Å. All Nb(1)-Se(2) bond lengths are 2.54 Å. Ga(1) is bonded to four equivalent Se(1) atoms to form GaSe4 tetrahedra that share corners with twelve equivalent Nb(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 64°. All Ga(1)-Se(1) bond lengths are 2.44 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Nb(1) and one Ga(1) atom to form a mixture of corner and edge-sharing SeNb3Ga tetrahedra. In the second Se site, Se(2) is bonded in a 3-coordinate geometry to three equivalent Nb(1) atoms.