AgInAl4Se8 crystallizes in the monoclinic C2 space group. Ag(1) is bonded to two equivalent Se(1) and two equivalent Se(3) atoms to form AgSe4 tetrahedra that share corners with two equivalent Al(1)Se4 tetrahedra, corners with two equivalent Al(2)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. In(1) is bonded to two equivalent Se(2) and two equivalent Se(4) atoms to form InSe4 tetrahedra that share corners with two equivalent Al(1)Se4 tetrahedra, corners with two equivalent Al(2)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent Se(2) and two equivalent Se(3) atoms to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. In the second Al site, Al(2) is bonded to two equivalent Se(1) and two equivalent Se(4) atoms to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. In the third Al site, Al(3) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, corners with two equivalent Al(1)Se4 tetrahedra, and corners with two equivalent Al(2)Se4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one Ag(1), one Al(2), and one Al(3) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one In(1), one Al(1), and one Al(3) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Ag(1), one Al(1), and one Al(3) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one In(1), one Al(2), and one Al(3) atom.
AgInAl4Se8 crystallizes in the monoclinic C2 space group. Ag(1) is bonded to two equivalent Se(1) and two equivalent Se(3) atoms to form AgSe4 tetrahedra that share corners with two equivalent Al(1)Se4 tetrahedra, corners with two equivalent Al(2)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. Both Ag(1)-Se(1) bond lengths are 2.63 Å. Both Ag(1)-Se(3) bond lengths are 2.63 Å. In(1) is bonded to two equivalent Se(2) and two equivalent Se(4) atoms to form InSe4 tetrahedra that share corners with two equivalent Al(1)Se4 tetrahedra, corners with two equivalent Al(2)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. Both In(1)-Se(2) bond lengths are 2.62 Å. Both In(1)-Se(4) bond lengths are 2.63 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent Se(2) and two equivalent Se(3) atoms to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. Both Al(1)-Se(2) bond lengths are 2.45 Å. Both Al(1)-Se(3) bond lengths are 2.35 Å. In the second Al site, Al(2) is bonded to two equivalent Se(1) and two equivalent Se(4) atoms to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, and corners with four equivalent Al(3)Se4 tetrahedra. Both Al(2)-Se(1) bond lengths are 2.35 Å. Both Al(2)-Se(4) bond lengths are 2.47 Å. In the third Al site, Al(3) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form AlSe4 tetrahedra that share corners with two equivalent Ag(1)Se4 tetrahedra, corners with two equivalent In(1)Se4 tetrahedra, corners with two equivalent Al(1)Se4 tetrahedra, and corners with two equivalent Al(2)Se4 tetrahedra. The Al(3)-Se(1) bond length is 2.36 Å. The Al(3)-Se(2) bond length is 2.45 Å. The Al(3)-Se(3) bond length is 2.35 Å. The Al(3)-Se(4) bond length is 2.45 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one Ag(1), one Al(2), and one Al(3) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one In(1), one Al(1), and one Al(3) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one Ag(1), one Al(1), and one Al(3) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one In(1), one Al(2), and one Al(3) atom.