CaTb4(PO4)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(13), one O(3), and one O(8) atom. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(6), and one O(9) atom. In the second Tb site, Tb(2) is bonded to one O(10), one O(12), one O(13), one O(2), one O(5), one O(6), and one O(7) atom to form distorted TbO7 pentagonal bipyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to one O(11), one O(16), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(15), one O(16), one O(4), one O(5), and one O(7) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded in a trigonal non-coplanar geometry to one O(13), one O(5), and one O(9) atom. In the second P site, P(2) is bonded to one O(10), one O(14), one O(2), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid and  an edgeedge with one Tb(2)O7 pentagonal bipyramid. In the third P site, P(3) is bonded to one O(11), one O(15), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid. In the fourth P site, P(4) is bonded to one O(12), one O(16), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Tb(1), and one Tb(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Tb(2), one Tb(3), and one P(2) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Ca(1), one Tb(1), one Tb(3), and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Tb(4) and one P(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tb(2), one Tb(4), and one P(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Tb(1), one Tb(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Tb(2), one Tb(3), one Tb(4), and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Tb(3), and one P(4) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Tb(1), one Tb(3), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Tb(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Tb(1), one Tb(3), and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Tb(2), one Tb(4), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Ca(1), one Tb(1), one Tb(2), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Tb(1) and one P(2) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Tb(4) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Tb(3), one Tb(4), and one P(4) atom.
CaTb4(PO4)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(13), one O(3), and one O(8) atom. The Ca(1)-O(1) bond length is 2.19 Å. The Ca(1)-O(10) bond length is 2.50 Å. The Ca(1)-O(13) bond length is 2.54 Å. The Ca(1)-O(3) bond length is 2.38 Å. The Ca(1)-O(8) bond length is 2.47 Å. There are four inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(6), and one O(9) atom. The Tb(1)-O(1) bond length is 2.13 Å. The Tb(1)-O(11) bond length is 2.42 Å. The Tb(1)-O(13) bond length is 2.35 Å. The Tb(1)-O(14) bond length is 2.21 Å. The Tb(1)-O(3) bond length is 2.87 Å. The Tb(1)-O(6) bond length is 2.76 Å. The Tb(1)-O(9) bond length is 2.76 Å. In the second Tb site, Tb(2) is bonded to one O(10), one O(12), one O(13), one O(2), one O(5), one O(6), and one O(7) atom to form distorted TbO7 pentagonal bipyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The Tb(2)-O(10) bond length is 2.26 Å. The Tb(2)-O(12) bond length is 2.27 Å. The Tb(2)-O(13) bond length is 2.51 Å. The Tb(2)-O(2) bond length is 2.49 Å. The Tb(2)-O(5) bond length is 2.52 Å. The Tb(2)-O(6) bond length is 2.35 Å. The Tb(2)-O(7) bond length is 2.36 Å. In the third Tb site, Tb(3) is bonded in a 7-coordinate geometry to one O(11), one O(16), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. The Tb(3)-O(11) bond length is 2.34 Å. The Tb(3)-O(16) bond length is 2.24 Å. The Tb(3)-O(2) bond length is 2.35 Å. The Tb(3)-O(3) bond length is 2.58 Å. The Tb(3)-O(7) bond length is 2.58 Å. The Tb(3)-O(8) bond length is 2.27 Å. The Tb(3)-O(9) bond length is 2.25 Å. In the fourth Tb site, Tb(4) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(15), one O(16), one O(4), one O(5), and one O(7) atom. The Tb(4)-O(1) bond length is 2.18 Å. The Tb(4)-O(12) bond length is 2.54 Å. The Tb(4)-O(15) bond length is 2.28 Å. The Tb(4)-O(16) bond length is 2.48 Å. The Tb(4)-O(4) bond length is 2.25 Å. The Tb(4)-O(5) bond length is 2.43 Å. The Tb(4)-O(7) bond length is 2.48 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded in a trigonal non-coplanar geometry to one O(13), one O(5), and one O(9) atom. The P(1)-O(13) bond length is 1.70 Å. The P(1)-O(5) bond length is 1.59 Å. The P(1)-O(9) bond length is 1.61 Å. In the second P site, P(2) is bonded to one O(10), one O(14), one O(2), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid and  an edgeedge with one Tb(2)O7 pentagonal bipyramid. The P(2)-O(10) bond length is 1.55 Å. The P(2)-O(14) bond length is 1.52 Å. The P(2)-O(2) bond length is 1.56 Å. The P(2)-O(6) bond length is 1.58 Å. In the third P site, P(3) is bonded to one O(11), one O(15), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid. The P(3)-O(11) bond length is 1.56 Å. The P(3)-O(15) bond length is 1.52 Å. The P(3)-O(3) bond length is 1.55 Å. The P(3)-O(7) bond length is 1.58 Å. In the fourth P site, P(4) is bonded to one O(12), one O(16), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Tb(2)O7 pentagonal bipyramid. The P(4)-O(12) bond length is 1.57 Å. The P(4)-O(16) bond length is 1.56 Å. The P(4)-O(4) bond length is 1.52 Å. The P(4)-O(8) bond length is 1.56 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Tb(1), and one Tb(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Tb(2), one Tb(3), and one P(2) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Ca(1), one Tb(1), one Tb(3), and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Tb(4) and one P(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Tb(2), one Tb(4), and one P(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Tb(1), one Tb(2), and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Tb(2), one Tb(3), one Tb(4), and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Tb(3), and one P(4) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Tb(1), one Tb(3), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Tb(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Tb(1), one Tb(3), and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Tb(2), one Tb(4), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Ca(1), one Tb(1), one Tb(2), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Tb(1) and one P(2) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Tb(4) and one P(3) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Tb(3), one Tb(4), and one P(4) atom.