Ni7Tl4(PO4)6 crystallizes in the monoclinic Cm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(13), one O(2), two equivalent O(14), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-60°. In the second Ni site, Ni(2) is bonded to one O(1), one O(10), one O(11), one O(4), one O(5), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Ni(3)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-60°. In the third Ni site, Ni(3) is bonded to one O(1), one O(14), one O(3), one O(5), one O(7), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(12), one O(4), one O(6), one O(7), and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-63°. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted single-bond geometry to one O(2) atom. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(11), one O(3), and one O(7) atom. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to two equivalent O(14) and two equivalent O(8) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. In the second P site, P(2) is bonded to one O(11), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-58°. In the third P site, P(3) is bonded to one O(1), one O(10), one O(14), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-55°. In the fourth P site, P(4) is bonded to one O(12), one O(13), and two equivalent O(9) atoms to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one P(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Tl(1), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ni(3), one Tl(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(2), one Ni(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Ni(4) and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ni(3), one Ni(4), one Tl(2), and one P(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ni(1), one Ni(2), one Tl(3), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ni(3), one Ni(4), and one P(4) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ni(2), one Ni(4), one Tl(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to two equivalent Ni(4) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ni(1), one Ni(3), one Tl(3), and one P(3) atom.
Ni7Tl4(PO4)6 crystallizes in the monoclinic Cm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(13), one O(2), two equivalent O(14), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-60°. The Ni(1)-O(13) bond length is 2.05 Å. The Ni(1)-O(2) bond length is 2.03 Å. Both Ni(1)-O(14) bond lengths are 2.11 Å. Both Ni(1)-O(8) bond lengths are 2.14 Å. In the second Ni site, Ni(2) is bonded to one O(1), one O(10), one O(11), one O(4), one O(5), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one Ni(3)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-60°. The Ni(2)-O(1) bond length is 2.14 Å. The Ni(2)-O(10) bond length is 2.17 Å. The Ni(2)-O(11) bond length is 2.18 Å. The Ni(2)-O(4) bond length is 2.05 Å. The Ni(2)-O(5) bond length is 2.08 Å. The Ni(2)-O(8) bond length is 2.09 Å. In the third Ni site, Ni(3) is bonded to one O(1), one O(14), one O(3), one O(5), one O(7), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. The Ni(3)-O(1) bond length is 2.07 Å. The Ni(3)-O(14) bond length is 2.14 Å. The Ni(3)-O(3) bond length is 2.15 Å. The Ni(3)-O(5) bond length is 2.17 Å. The Ni(3)-O(7) bond length is 2.11 Å. The Ni(3)-O(9) bond length is 2.09 Å. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(12), one O(4), one O(6), one O(7), and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-63°. The Ni(4)-O(11) bond length is 2.08 Å. The Ni(4)-O(12) bond length is 2.18 Å. The Ni(4)-O(4) bond length is 2.12 Å. The Ni(4)-O(6) bond length is 2.26 Å. The Ni(4)-O(7) bond length is 2.07 Å. The Ni(4)-O(9) bond length is 2.16 Å. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a distorted single-bond geometry to one O(2) atom. The Tl(1)-O(2) bond length is 2.71 Å. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to one O(11), one O(3), and one O(7) atom. The Tl(2)-O(11) bond length is 2.72 Å. The Tl(2)-O(3) bond length is 2.80 Å. The Tl(2)-O(7) bond length is 2.67 Å. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to two equivalent O(14) and two equivalent O(8) atoms. Both Tl(3)-O(14) bond lengths are 2.76 Å. Both Tl(3)-O(8) bond lengths are 2.73 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. The P(1)-O(2) bond length is 1.51 Å. The P(1)-O(6) bond length is 1.57 Å. Both P(1)-O(4) bond lengths are 1.57 Å. In the second P site, P(2) is bonded to one O(11), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 21-58°. The P(2)-O(11) bond length is 1.59 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(8) bond length is 1.58 Å. In the third P site, P(3) is bonded to one O(1), one O(10), one O(14), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-55°. The P(3)-O(1) bond length is 1.56 Å. The P(3)-O(10) bond length is 1.53 Å. The P(3)-O(14) bond length is 1.57 Å. The P(3)-O(7) bond length is 1.60 Å. In the fourth P site, P(4) is bonded to one O(12), one O(13), and two equivalent O(9) atoms to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The P(4)-O(12) bond length is 1.58 Å. The P(4)-O(13) bond length is 1.52 Å. Both P(4)-O(9) bond lengths are 1.58 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one P(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Tl(1), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ni(3), one Tl(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(2), one Ni(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Ni(4) and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ni(3), one Ni(4), one Tl(2), and one P(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ni(1), one Ni(2), one Tl(3), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ni(3), one Ni(4), and one P(4) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ni(2), one Ni(4), one Tl(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to two equivalent Ni(4) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ni(1), one Ni(3), one Tl(3), and one P(3) atom.