CaThNb2O8 crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Th(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted tetrahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Nb site, Nb(2) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Th(1), one Nb(1), and one Nb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Th(1), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Th(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Th(1), and one Nb(2) atom.
CaThNb2O8 crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Ca(1)-O(1) bond lengths are 2.46 Å. Both Ca(1)-O(2) bond lengths are 2.52 Å. Both Ca(1)-O(3) bond lengths are 2.43 Å. Both Ca(1)-O(4) bond lengths are 2.49 Å. Th(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Th(1)-O(1) bond lengths are 2.48 Å. Both Th(1)-O(2) bond lengths are 2.40 Å. Both Th(1)-O(3) bond lengths are 2.44 Å. Both Th(1)-O(4) bond lengths are 2.39 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted tetrahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Nb(1)-O(1) bond lengths are 1.95 Å. Both Nb(1)-O(2) bond lengths are 2.54 Å. Both Nb(1)-O(3) bond lengths are 1.88 Å. In the second Nb site, Nb(2) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Both Nb(2)-O(1) bond lengths are 2.50 Å. Both Nb(2)-O(2) bond lengths are 1.95 Å. Both Nb(2)-O(4) bond lengths are 1.88 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Th(1), one Nb(1), and one Nb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Th(1), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Th(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Th(1), and one Nb(2) atom.