Li2Th(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(4) and two equivalent O(8) atoms. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(6), one O(7), and one O(8) atom. Th(1) is bonded in a 9-coordinate geometry to one O(2), one O(5), one O(7), two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(5), and one O(8) atom. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(1), one O(4), one O(6), and one O(7) atom. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a trigonal planar geometry to two equivalent Li(1) and one As(2) atom. In the second O site, O(5) is bonded in a water-like geometry to one Th(1) and one As(1) atom. In the third O site, O(6) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Th(1), and one As(2) atom. In the fourth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Th(1), and one As(2) atom. In the fifth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), two equivalent Li(1), and one As(1) atom. In the sixth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Th(1) and one As(2) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Th(1), and one As(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Th(1) and one As(1) atom.
Li2Th(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(4) and two equivalent O(8) atoms. Both Li(1)-O(4) bond lengths are 1.91 Å. There is one shorter (2.05 Å) and one longer (2.07 Å) Li(1)-O(8) bond length. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(6), one O(7), and one O(8) atom. The Li(2)-O(2) bond length is 1.97 Å. The Li(2)-O(6) bond length is 2.10 Å. The Li(2)-O(7) bond length is 2.19 Å. The Li(2)-O(8) bond length is 2.08 Å. Th(1) is bonded in a 9-coordinate geometry to one O(2), one O(5), one O(7), two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms. The Th(1)-O(2) bond length is 2.39 Å. The Th(1)-O(5) bond length is 2.37 Å. The Th(1)-O(7) bond length is 2.43 Å. There is one shorter (2.49 Å) and one longer (2.50 Å) Th(1)-O(1) bond length. There is one shorter (2.43 Å) and one longer (2.67 Å) Th(1)-O(3) bond length. There is one shorter (2.61 Å) and one longer (2.67 Å) Th(1)-O(6) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(2), one O(3), one O(5), and one O(8) atom. The As(1)-O(2) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.75 Å. The As(1)-O(5) bond length is 1.71 Å. The As(1)-O(8) bond length is 1.70 Å. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(1), one O(4), one O(6), and one O(7) atom. The As(2)-O(1) bond length is 1.75 Å. The As(2)-O(4) bond length is 1.68 Å. The As(2)-O(6) bond length is 1.75 Å. The As(2)-O(7) bond length is 1.72 Å. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a trigonal planar geometry to two equivalent Li(1) and one As(2) atom. In the second O site, O(5) is bonded in a water-like geometry to one Th(1) and one As(1) atom. In the third O site, O(6) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Th(1), and one As(2) atom. In the fourth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Th(1), and one As(2) atom. In the fifth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), two equivalent Li(1), and one As(1) atom. In the sixth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Th(1) and one As(2) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Th(1), and one As(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Th(1) and one As(1) atom.