Ga2Se3 crystallizes in the monoclinic Cc space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form corner-sharing GaSe4 tetrahedra. In the second Ga site, Ga(2) is bonded to one Se(2), one Se(3), and two equivalent Se(1) atoms to form corner-sharing GaSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the second Se site, Se(2) is bonded in a water-like geometry to one Ga(1) and one Ga(2) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Ga(2) and two equivalent Ga(1) atoms.
Ga2Se3 crystallizes in the monoclinic Cc space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form corner-sharing GaSe4 tetrahedra. The Ga(1)-Se(1) bond length is 2.45 Å. The Ga(1)-Se(2) bond length is 2.35 Å. There is one shorter (2.46 Å) and one longer (2.47 Å) Ga(1)-Se(3) bond length. In the second Ga site, Ga(2) is bonded to one Se(2), one Se(3), and two equivalent Se(1) atoms to form corner-sharing GaSe4 tetrahedra. The Ga(2)-Se(2) bond length is 2.34 Å. The Ga(2)-Se(3) bond length is 2.46 Å. Both Ga(2)-Se(1) bond lengths are 2.46 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the second Se site, Se(2) is bonded in a water-like geometry to one Ga(1) and one Ga(2) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Ga(2) and two equivalent Ga(1) atoms.