NaInI4 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form NaI6 octahedra that share corners with two equivalent Na(1)I6 octahedra, corners with two equivalent In(1)I4 tetrahedra,  an edgeedge with one Na(1)I6 octahedra, and edges with two equivalent In(1)I4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. In(1) is bonded to one I(1), one I(2), one I(3), and one I(4) atom to form InI4 tetrahedra that share corners with two equivalent Na(1)I6 octahedra and edges with two equivalent Na(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 64-66°. There are four inequivalent I sites. In the first I site, I(1) is bonded in an L-shaped geometry to one Na(1) and one In(1) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to two equivalent Na(1) and one In(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one In(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Na(1) and one In(1) atom.
NaInI4 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form NaI6 octahedra that share corners with two equivalent Na(1)I6 octahedra, corners with two equivalent In(1)I4 tetrahedra,  an edgeedge with one Na(1)I6 octahedra, and edges with two equivalent In(1)I4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. The Na(1)-I(1) bond length is 3.16 Å. The Na(1)-I(4) bond length is 3.20 Å. There is one shorter (3.30 Å) and one longer (3.31 Å) Na(1)-I(2) bond length. Both Na(1)-I(3) bond lengths are 3.30 Å. In(1) is bonded to one I(1), one I(2), one I(3), and one I(4) atom to form InI4 tetrahedra that share corners with two equivalent Na(1)I6 octahedra and edges with two equivalent Na(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 64-66°. The In(1)-I(1) bond length is 2.72 Å. The In(1)-I(2) bond length is 2.77 Å. The In(1)-I(3) bond length is 2.77 Å. The In(1)-I(4) bond length is 2.72 Å. There are four inequivalent I sites. In the first I site, I(1) is bonded in an L-shaped geometry to one Na(1) and one In(1) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to two equivalent Na(1) and one In(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one In(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Na(1) and one In(1) atom.