In2Se3 crystallizes in the hexagonal P6_5 space group. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 3-coordinate geometry to one Se(3) and two equivalent Se(1) atoms. In the second In site, In(2) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form distorted corner-sharing InSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one In(2) and two equivalent In(1) atoms. In the second Se site, Se(2) is bonded in a 2-coordinate geometry to one In(2) and one Se(3) atom. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one In(1), two equivalent In(2), and one Se(2) atom.
In2Se3 crystallizes in the hexagonal P6_5 space group. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 3-coordinate geometry to one Se(3) and two equivalent Se(1) atoms. The In(1)-Se(3) bond length is 3.25 Å. There is one shorter (2.95 Å) and one longer (3.06 Å) In(1)-Se(1) bond length. In the second In site, In(2) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form distorted corner-sharing InSe4 tetrahedra. The In(2)-Se(1) bond length is 2.51 Å. The In(2)-Se(2) bond length is 2.60 Å. There is one shorter (2.72 Å) and one longer (2.96 Å) In(2)-Se(3) bond length. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one In(2) and two equivalent In(1) atoms. In the second Se site, Se(2) is bonded in a 2-coordinate geometry to one In(2) and one Se(3) atom. The Se(2)-Se(3) bond length is 2.44 Å. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one In(1), two equivalent In(2), and one Se(2) atom.