LiAlSi2O6 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Al(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-60°. In the second Si site, Si(2) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-58°. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to one Li(1) and two equivalent Si(2) atoms. In the third O site, O(1) is bonded to one Li(1), two equivalent Al(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si trigonal pyramids. In the fourth O site, O(2) is bonded in a T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. In the sixth O site, O(4) is bonded to one Li(1), two equivalent Al(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si trigonal pyramids.
LiAlSi2O6 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Li(1)-O(1) bond length is 2.11 Å. The Li(1)-O(2) bond length is 2.23 Å. The Li(1)-O(3) bond length is 2.19 Å. The Li(1)-O(4) bond length is 2.09 Å. The Li(1)-O(5) bond length is 2.11 Å. The Li(1)-O(6) bond length is 2.56 Å. Al(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. The Al(1)-O(2) bond length is 1.84 Å. The Al(1)-O(5) bond length is 1.86 Å. There is one shorter (1.93 Å) and one longer (2.05 Å) Al(1)-O(1) bond length. There is one shorter (1.95 Å) and one longer (2.05 Å) Al(1)-O(4) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-60°. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(2) bond length is 1.60 Å. Both Si(1)-O(3) bond lengths are 1.65 Å. In the second Si site, Si(2) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-58°. The Si(2)-O(4) bond length is 1.67 Å. The Si(2)-O(5) bond length is 1.61 Å. Both Si(2)-O(6) bond lengths are 1.65 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Al(1), and one Si(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to one Li(1) and two equivalent Si(2) atoms. In the third O site, O(1) is bonded to one Li(1), two equivalent Al(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si trigonal pyramids. In the fourth O site, O(2) is bonded in a T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. In the sixth O site, O(4) is bonded to one Li(1), two equivalent Al(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si trigonal pyramids.