LiTl6Si2O7 crystallizes in the triclinic P1 space group. Li(1) is bonded in a bent 120 degrees geometry to one Tl(4), one O(3), and one O(6) atom. There are six inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one O(3) and one O(6) atom. In the second Tl site, Tl(2) is bonded in an L-shaped geometry to one O(1) and one O(4) atom. In the third Tl site, Tl(3) is bonded in a 2-coordinate geometry to one O(2) and one O(5) atom. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one Li(1), one O(4), one O(6), and one O(7) atom. In the fifth Tl site, Tl(5) is bonded in a distorted T-shaped geometry to one O(1), one O(4), and one O(7) atom. In the sixth Tl site, Tl(6) is bonded in a distorted T-shaped geometry to one O(2), one O(5), and one O(7) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(4), one O(5), one O(6), and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Tl(2), one Tl(5), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Tl(3), one Tl(6), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Tl(1), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Tl(2), one Tl(4), one Tl(5), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OTl3Si trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tl(3), one Tl(6), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Tl(1), one Tl(4), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Tl(4), one Tl(5), one Tl(6), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OTl3Si tetrahedra.
LiTl6Si2O7 crystallizes in the triclinic P1 space group. Li(1) is bonded in a bent 120 degrees geometry to one Tl(4), one O(3), and one O(6) atom. The Li(1)-Tl(4) bond length is 2.89 Å. The Li(1)-O(3) bond length is 1.83 Å. The Li(1)-O(6) bond length is 1.84 Å. There are six inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 2-coordinate geometry to one O(3) and one O(6) atom. The Tl(1)-O(3) bond length is 2.69 Å. The Tl(1)-O(6) bond length is 2.58 Å. In the second Tl site, Tl(2) is bonded in an L-shaped geometry to one O(1) and one O(4) atom. The Tl(2)-O(1) bond length is 2.56 Å. The Tl(2)-O(4) bond length is 2.51 Å. In the third Tl site, Tl(3) is bonded in a 2-coordinate geometry to one O(2) and one O(5) atom. The Tl(3)-O(2) bond length is 2.63 Å. The Tl(3)-O(5) bond length is 2.34 Å. In the fourth Tl site, Tl(4) is bonded in a 4-coordinate geometry to one Li(1), one O(4), one O(6), and one O(7) atom. The Tl(4)-O(4) bond length is 2.51 Å. The Tl(4)-O(6) bond length is 2.57 Å. The Tl(4)-O(7) bond length is 2.50 Å. In the fifth Tl site, Tl(5) is bonded in a distorted T-shaped geometry to one O(1), one O(4), and one O(7) atom. The Tl(5)-O(1) bond length is 2.57 Å. The Tl(5)-O(4) bond length is 2.50 Å. The Tl(5)-O(7) bond length is 2.55 Å. In the sixth Tl site, Tl(6) is bonded in a distorted T-shaped geometry to one O(2), one O(5), and one O(7) atom. The Tl(6)-O(2) bond length is 2.57 Å. The Tl(6)-O(5) bond length is 2.52 Å. The Tl(6)-O(7) bond length is 2.63 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.61 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(4), one O(5), one O(6), and one O(7) atom. The Si(2)-O(4) bond length is 1.67 Å. The Si(2)-O(5) bond length is 1.65 Å. The Si(2)-O(6) bond length is 1.67 Å. The Si(2)-O(7) bond length is 1.66 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Tl(2), one Tl(5), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Tl(3), one Tl(6), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Tl(1), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Tl(2), one Tl(4), one Tl(5), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OTl3Si trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tl(3), one Tl(6), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Tl(1), one Tl(4), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Tl(4), one Tl(5), one Tl(6), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OTl3Si tetrahedra.