LiGaSi2O6 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted LiO5 square pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with three equivalent Ga(1)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. Ga(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form GaO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, edges with two equivalent Ga(1)O6 octahedra, and edges with three equivalent Li(1)O5 square pyramids. 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(4) atoms to form SiO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 35-59°. In the second Si site, Si(2) is bonded to one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Ga(1), and one Si(2) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Li(1), one Ga(1), and one Si(1) atom. In the third O site, O(2) is bonded to one Li(1), two equivalent Ga(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiGa2Si trigonal pyramids. In the fourth O site, O(3) is bonded to one Li(1), two equivalent Ga(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLiGa2Si trigonal pyramids. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms.
LiGaSi2O6 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted LiO5 square pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, edges with three equivalent Ga(1)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The Li(1)-O(1) bond length is 2.16 Å. The Li(1)-O(2) bond length is 2.07 Å. The Li(1)-O(3) bond length is 2.08 Å. The Li(1)-O(4) bond length is 2.39 Å. The Li(1)-O(6) bond length is 2.11 Å. Ga(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form GaO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, edges with two equivalent Ga(1)O6 octahedra, and edges with three equivalent Li(1)O5 square pyramids. The Ga(1)-O(1) bond length is 1.92 Å. The Ga(1)-O(6) bond length is 1.93 Å. There is one shorter (2.00 Å) and one longer (2.15 Å) Ga(1)-O(2) bond length. There is one shorter (2.00 Å) and one longer (2.15 Å) Ga(1)-O(3) 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(4) atoms to form SiO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, corners with two equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 35-59°. The Si(1)-O(1) bond length is 1.61 Å. The Si(1)-O(2) bond length is 1.66 Å. There is one shorter (1.64 Å) and one longer (1.65 Å) Si(1)-O(4) bond length. In the second Si site, Si(2) is bonded to one O(3), one O(6), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with three equivalent Ga(1)O6 octahedra, corners with two equivalent Li(1)O5 square pyramids, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. The Si(2)-O(3) bond length is 1.67 Å. The Si(2)-O(6) bond length is 1.61 Å. Both Si(2)-O(5) bond lengths are 1.64 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Ga(1), and one Si(2) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Li(1), one Ga(1), and one Si(1) atom. In the third O site, O(2) is bonded to one Li(1), two equivalent Ga(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiGa2Si trigonal pyramids. In the fourth O site, O(3) is bonded to one Li(1), two equivalent Ga(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLiGa2Si trigonal pyramids. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms.