Li2Cu(SiO3)2 crystallizes in the orthorhombic Fdd2 space group. Li(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent Cu(1)O4 tetrahedra, and corners with five equivalent Si(1)O4 tetrahedra. Cu(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CuO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and corners with six equivalent Li(1)O4 tetrahedra. 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 two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with five equivalent Li(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Li(1), one Cu(1), and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one Si(1) atom to form corner-sharing OLi2CuSi tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Li(1) and two equivalent Si(1) atoms.
Li2Cu(SiO3)2 crystallizes in the orthorhombic Fdd2 space group. Li(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with three equivalent Cu(1)O4 tetrahedra, and corners with five equivalent Si(1)O4 tetrahedra. The Li(1)-O(1) bond length is 1.97 Å. The Li(1)-O(3) bond length is 2.30 Å. Both Li(1)-O(2) bond lengths are 2.00 Å. Cu(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CuO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and corners with six equivalent Li(1)O4 tetrahedra. Both Cu(1)-O(1) bond lengths are 1.91 Å. Both Cu(1)-O(2) bond lengths are 2.06 Å. 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 two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with five equivalent Li(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.63 Å. There is one shorter (1.66 Å) and one longer (1.67 Å) Si(1)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Li(1), one Cu(1), and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one Si(1) atom to form corner-sharing OLi2CuSi tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Li(1) and two equivalent Si(1) atoms.