ThLa2Ta(O2Cl)3 crystallizes in the monoclinic Pm space group. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(6), one Cl(1), one Cl(2), and two equivalent Cl(6) atoms. In the second Th site, Th(2) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), one Cl(2), one Cl(3), and two equivalent Cl(4) atoms. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 10-coordinate geometry to two equivalent O(3), two equivalent O(5), two equivalent O(6), one Cl(1), one Cl(3), and two equivalent Cl(5) atoms. In the second La site, La(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), one Cl(4), one Cl(5), and two equivalent Cl(3) atoms. In the third La site, La(3) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), one Cl(5), one Cl(6), and two equivalent Cl(1) atoms. In the fourth La site, La(4) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(6), one Cl(4), one Cl(6), and two equivalent Cl(2) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted pentagonal pyramidal geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. In the second Ta site, Ta(2) is bonded in a distorted pentagonal pyramidal geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one La(2), one La(3), and one Ta(2) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(1)La2ThTa tetrahedra. In the second O site, O(2) is bonded to one Th(2), one La(3), one La(4), and one Ta(2) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra, and edges with two equivalent O(2)La2ThTa tetrahedra. In the third O site, O(3) is bonded to one La(1), one La(2), one La(4), and one Ta(2) atom to form OLa3Ta tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra, and edges with two equivalent O(3)La3Ta tetrahedra. In the fourth O site, O(4) is bonded to one Th(1), one Th(2), one La(2), and one Ta(1) atom to form distorted OLaTh2Ta tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra, and edges with two equivalent O(4)LaTh2Ta tetrahedra. In the fifth O site, O(5) is bonded to one Th(2), one La(1), one La(3), and one Ta(1) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(5)La2ThTa tetrahedra. In the sixth O site, O(6) is bonded to one Th(1), one La(1), one La(4), and one Ta(1) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(6)La2ThTa tetrahedra. There are six inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a see-saw-like geometry to one Th(1), one La(1), and two equivalent La(3) atoms. In the second Cl site, Cl(2) is bonded in a see-saw-like geometry to one Th(1), one Th(2), and two equivalent La(4) atoms. In the third Cl site, Cl(3) is bonded in a see-saw-like geometry to one Th(2), one La(1), and two equivalent La(2) atoms. In the fourth Cl site, Cl(4) is bonded in a see-saw-like geometry to two equivalent Th(2), one La(2), and one La(4) atom. In the fifth Cl site, Cl(5) is bonded in a see-saw-like geometry to one La(2), one La(3), and two equivalent La(1) atoms. In the sixth Cl site, Cl(6) is bonded in a see-saw-like geometry to two equivalent Th(1), one La(3), and one La(4) atom.
ThLa2Ta(O2Cl)3 crystallizes in the monoclinic Pm space group. There are two inequivalent Th sites. In the first Th site, Th(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(6), one Cl(1), one Cl(2), and two equivalent Cl(6) atoms. Both Th(1)-O(1) bond lengths are 2.44 Å. Both Th(1)-O(4) bond lengths are 2.33 Å. Both Th(1)-O(6) bond lengths are 2.62 Å. The Th(1)-Cl(1) bond length is 3.08 Å. The Th(1)-Cl(2) bond length is 3.10 Å. Both Th(1)-Cl(6) bond lengths are 3.12 Å. In the second Th site, Th(2) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), one Cl(2), one Cl(3), and two equivalent Cl(4) atoms. Both Th(2)-O(2) bond lengths are 2.40 Å. Both Th(2)-O(4) bond lengths are 2.73 Å. Both Th(2)-O(5) bond lengths are 2.30 Å. The Th(2)-Cl(2) bond length is 3.12 Å. The Th(2)-Cl(3) bond length is 3.05 Å. Both Th(2)-Cl(4) bond lengths are 3.12 Å. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 10-coordinate geometry to two equivalent O(3), two equivalent O(5), two equivalent O(6), one Cl(1), one Cl(3), and two equivalent Cl(5) atoms. Both La(1)-O(3) bond lengths are 2.51 Å. Both La(1)-O(5) bond lengths are 2.77 Å. Both La(1)-O(6) bond lengths are 2.44 Å. The La(1)-Cl(1) bond length is 3.08 Å. The La(1)-Cl(3) bond length is 3.09 Å. Both La(1)-Cl(5) bond lengths are 3.08 Å. In the second La site, La(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), one Cl(4), one Cl(5), and two equivalent Cl(3) atoms. Both La(2)-O(1) bond lengths are 2.44 Å. Both La(2)-O(3) bond lengths are 2.60 Å. Both La(2)-O(4) bond lengths are 2.59 Å. The La(2)-Cl(4) bond length is 3.07 Å. The La(2)-Cl(5) bond length is 3.02 Å. Both La(2)-Cl(3) bond lengths are 3.10 Å. In the third La site, La(3) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), one Cl(5), one Cl(6), and two equivalent Cl(1) atoms. Both La(3)-O(1) bond lengths are 2.69 Å. Both La(3)-O(2) bond lengths are 2.44 Å. Both La(3)-O(5) bond lengths are 2.54 Å. The La(3)-Cl(5) bond length is 3.06 Å. The La(3)-Cl(6) bond length is 2.98 Å. Both La(3)-Cl(1) bond lengths are 3.10 Å. In the fourth La site, La(4) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(6), one Cl(4), one Cl(6), and two equivalent Cl(2) atoms. Both La(4)-O(2) bond lengths are 2.73 Å. Both La(4)-O(3) bond lengths are 2.41 Å. Both La(4)-O(6) bond lengths are 2.56 Å. The La(4)-Cl(4) bond length is 3.05 Å. The La(4)-Cl(6) bond length is 3.05 Å. Both La(4)-Cl(2) bond lengths are 3.10 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted pentagonal pyramidal geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. Both Ta(1)-O(4) bond lengths are 2.02 Å. Both Ta(1)-O(5) bond lengths are 2.02 Å. Both Ta(1)-O(6) bond lengths are 2.00 Å. In the second Ta site, Ta(2) is bonded in a distorted pentagonal pyramidal geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Ta(2)-O(1) bond lengths are 2.02 Å. Both Ta(2)-O(2) bond lengths are 2.02 Å. Both Ta(2)-O(3) bond lengths are 1.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Th(1), one La(2), one La(3), and one Ta(2) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(1)La2ThTa tetrahedra. In the second O site, O(2) is bonded to one Th(2), one La(3), one La(4), and one Ta(2) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra, and edges with two equivalent O(2)La2ThTa tetrahedra. In the third O site, O(3) is bonded to one La(1), one La(2), one La(4), and one Ta(2) atom to form OLa3Ta tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra, and edges with two equivalent O(3)La3Ta tetrahedra. In the fourth O site, O(4) is bonded to one Th(1), one Th(2), one La(2), and one Ta(1) atom to form distorted OLaTh2Ta tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra,  an edgeedge with one O(1)La2ThTa tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra, and edges with two equivalent O(4)LaTh2Ta tetrahedra. In the fifth O site, O(5) is bonded to one Th(2), one La(1), one La(3), and one Ta(1) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(6)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(2)La2ThTa tetrahedra,  an edgeedge with one O(6)La2ThTa tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(5)La2ThTa tetrahedra. In the sixth O site, O(6) is bonded to one Th(1), one La(1), one La(4), and one Ta(1) atom to form distorted OLa2ThTa tetrahedra that share corners with two equivalent O(1)La2ThTa tetrahedra, corners with two equivalent O(2)La2ThTa tetrahedra, corners with two equivalent O(5)La2ThTa tetrahedra, corners with two equivalent O(3)La3Ta tetrahedra, corners with two equivalent O(4)LaTh2Ta tetrahedra,  an edgeedge with one O(5)La2ThTa tetrahedra,  an edgeedge with one O(3)La3Ta tetrahedra,  an edgeedge with one O(4)LaTh2Ta tetrahedra, and edges with two equivalent O(6)La2ThTa tetrahedra. There are six inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a see-saw-like geometry to one Th(1), one La(1), and two equivalent La(3) atoms. In the second Cl site, Cl(2) is bonded in a see-saw-like geometry to one Th(1), one Th(2), and two equivalent La(4) atoms. In the third Cl site, Cl(3) is bonded in a see-saw-like geometry to one Th(2), one La(1), and two equivalent La(2) atoms. In the fourth Cl site, Cl(4) is bonded in a see-saw-like geometry to two equivalent Th(2), one La(2), and one La(4) atom. In the fifth Cl site, Cl(5) is bonded in a see-saw-like geometry to one La(2), one La(3), and two equivalent La(1) atoms. In the sixth Cl site, Cl(6) is bonded in a see-saw-like geometry to two equivalent Th(1), one La(3), and one La(4) atom.