In4N2Se3 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent Se(1), and two equivalent Se(2) atoms. In the second In site, In(2) is bonded in a distorted bent 120 degrees geometry to two equivalent N(1), one Se(1), and three equivalent Se(2) atoms. N(1) is bonded to two equivalent In(1) and two equivalent In(2) atoms to form NIn4 tetrahedra that share corners with two equivalent Se(1)In6 octahedra, corners with two equivalent N(1)In4 tetrahedra, corners with four equivalent Se(2)In5 trigonal bipyramids, edges with two equivalent Se(1)In6 octahedra,  an edgeedge with one N(1)In4 tetrahedra, and edges with three equivalent Se(2)In5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent In(2) and four equivalent In(1) atoms to form distorted SeIn6 octahedra that share corners with four equivalent N(1)In4 tetrahedra, corners with ten equivalent Se(2)In5 trigonal bipyramids, edges with two equivalent Se(1)In6 octahedra, edges with four equivalent N(1)In4 tetrahedra, and edges with two equivalent Se(2)In5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent In(1) and three equivalent In(2) atoms to form distorted SeIn5 trigonal bipyramids that share corners with five equivalent Se(1)In6 octahedra, corners with four equivalent N(1)In4 tetrahedra, corners with four equivalent Se(2)In5 trigonal bipyramids,  an edgeedge with one Se(1)In6 octahedra, edges with three equivalent N(1)In4 tetrahedra, and edges with two equivalent Se(2)In5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 26-75°.
In4N2Se3 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent Se(1), and two equivalent Se(2) atoms. There is one shorter (2.17 Å) and one longer (2.29 Å) In(1)-N(1) bond length. Both In(1)-Se(1) bond lengths are 3.04 Å. Both In(1)-Se(2) bond lengths are 2.84 Å. In the second In site, In(2) is bonded in a distorted bent 120 degrees geometry to two equivalent N(1), one Se(1), and three equivalent Se(2) atoms. Both In(2)-N(1) bond lengths are 2.19 Å. The In(2)-Se(1) bond length is 3.07 Å. There is one shorter (2.83 Å) and two longer (2.92 Å) In(2)-Se(2) bond lengths. N(1) is bonded to two equivalent In(1) and two equivalent In(2) atoms to form NIn4 tetrahedra that share corners with two equivalent Se(1)In6 octahedra, corners with two equivalent N(1)In4 tetrahedra, corners with four equivalent Se(2)In5 trigonal bipyramids, edges with two equivalent Se(1)In6 octahedra,  an edgeedge with one N(1)In4 tetrahedra, and edges with three equivalent Se(2)In5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent In(2) and four equivalent In(1) atoms to form distorted SeIn6 octahedra that share corners with four equivalent N(1)In4 tetrahedra, corners with ten equivalent Se(2)In5 trigonal bipyramids, edges with two equivalent Se(1)In6 octahedra, edges with four equivalent N(1)In4 tetrahedra, and edges with two equivalent Se(2)In5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent In(1) and three equivalent In(2) atoms to form distorted SeIn5 trigonal bipyramids that share corners with five equivalent Se(1)In6 octahedra, corners with four equivalent N(1)In4 tetrahedra, corners with four equivalent Se(2)In5 trigonal bipyramids,  an edgeedge with one Se(1)In6 octahedra, edges with three equivalent N(1)In4 tetrahedra, and edges with two equivalent Se(2)In5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 26-75°.