LiAlAs2O7 crystallizes in the monoclinic C2 space group. Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent As(1) atoms.
LiAlAs2O7 crystallizes in the monoclinic C2 space group. Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Li(1)-O(1) bond lengths are 2.04 Å. Both Li(1)-O(2) bond lengths are 2.06 Å. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. Both Al(1)-O(1) bond lengths are 1.96 Å. Both Al(1)-O(2) bond lengths are 1.94 Å. Both Al(1)-O(3) bond lengths are 1.87 Å. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-55°. The As(1)-O(1) bond length is 1.71 Å. The As(1)-O(2) bond length is 1.71 Å. The As(1)-O(3) bond length is 1.68 Å. The As(1)-O(4) bond length is 1.78 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent As(1) atoms.