LiTl6Si2O7 crystallizes in the trigonal P3 space group. Li(1) is bonded in a trigonal non-coplanar geometry to three equivalent Tl(2) atoms. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted L-shaped geometry to one O(1) and one O(2) atom. In the second Tl site, Tl(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one O(1), one O(2), and one O(3) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3) and three equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Tl(1), one Tl(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Tl(1), one Tl(2), and one Si(2) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to three equivalent Tl(2) and one Si(2) atom.
LiTl6Si2O7 crystallizes in the trigonal P3 space group. Li(1) is bonded in a trigonal non-coplanar geometry to three equivalent Tl(2) atoms. All Li(1)-Tl(2) bond lengths are 2.95 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted L-shaped geometry to one O(1) and one O(2) atom. The Tl(1)-O(1) bond length is 2.71 Å. The Tl(1)-O(2) bond length is 2.44 Å. In the second Tl site, Tl(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one O(1), one O(2), and one O(3) atom. The Tl(2)-O(1) bond length is 2.52 Å. The Tl(2)-O(2) bond length is 2.41 Å. The Tl(2)-O(3) bond length is 2.48 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. All Si(1)-O(1) bond lengths are 1.60 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3) and three equivalent O(2) atoms. The Si(2)-O(3) bond length is 1.68 Å. All Si(2)-O(2) bond lengths are 1.65 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Tl(1), one Tl(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Tl(1), one Tl(2), and one Si(2) atom. In the third O site, O(3) is bonded in a tetrahedral geometry to three equivalent Tl(2) and one Si(2) atom.