In4Se3 crystallizes in the orthorhombic Pnnm space group. There are four inequivalent In sites. In the first In site, In(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. In the second In site, In(2) is bonded in a 3-coordinate geometry to one In(3), one Se(3), and two equivalent Se(1) atoms. In the third In site, In(3) is bonded in a distorted L-shaped geometry to one In(2), one In(4), and two equivalent Se(2) atoms. In the fourth In site, In(4) is bonded in a distorted trigonal non-coplanar geometry to one In(3), one Se(2), and two equivalent Se(3) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one In(1) and two equivalent In(2) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one In(4), two equivalent In(1), and two equivalent In(3) atoms. In the third Se site, Se(3) is bonded in a distorted trigonal non-coplanar geometry to one In(2) and two equivalent In(4) atoms.
In4Se3 crystallizes in the orthorhombic Pnnm space group. There are four inequivalent In sites. In the first In site, In(1) is bonded in a 3-coordinate geometry to one Se(1) and two equivalent Se(2) atoms. The In(1)-Se(1) bond length is 2.95 Å. Both In(1)-Se(2) bond lengths are 3.19 Å. In the second In site, In(2) is bonded in a 3-coordinate geometry to one In(3), one Se(3), and two equivalent Se(1) atoms. The In(2)-In(3) bond length is 2.78 Å. The In(2)-Se(3) bond length is 2.72 Å. Both In(2)-Se(1) bond lengths are 2.65 Å. In the third In site, In(3) is bonded in a distorted L-shaped geometry to one In(2), one In(4), and two equivalent Se(2) atoms. The In(3)-In(4) bond length is 2.81 Å. Both In(3)-Se(2) bond lengths are 2.81 Å. In the fourth In site, In(4) is bonded in a distorted trigonal non-coplanar geometry to one In(3), one Se(2), and two equivalent Se(3) atoms. The In(4)-Se(2) bond length is 2.66 Å. Both In(4)-Se(3) bond lengths are 2.70 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one In(1) and two equivalent In(2) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one In(4), two equivalent In(1), and two equivalent In(3) atoms. In the third Se site, Se(3) is bonded in a distorted trigonal non-coplanar geometry to one In(2) and two equivalent In(4) atoms.