CsAlSiO4 crystallizes in the orthorhombic Pna2_1 space group. Cs(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Cs(1), one Al(1), and one Si(1) atom.
CsAlSiO4 crystallizes in the orthorhombic Pna2_1 space group. Cs(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Cs(1)-O(4) bond length is 3.37 Å. There is one shorter (3.38 Å) and one longer (3.42 Å) Cs(1)-O(1) bond length. There is one shorter (3.24 Å) and one longer (3.30 Å) Cs(1)-O(2) bond length. There is one shorter (3.15 Å) and one longer (3.40 Å) Cs(1)-O(3) bond length. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. The Al(1)-O(1) bond length is 1.74 Å. The Al(1)-O(2) bond length is 1.77 Å. The Al(1)-O(3) bond length is 1.76 Å. The Al(1)-O(4) bond length is 1.75 Å. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Al(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.63 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Cs(1), one Al(1), and one Si(1) atom.