VNi(PO4)2 crystallizes in the triclinic P1 space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(11), one O(12), one O(15), one O(16), one O(2), and one O(6) atom to form VO6 octahedra that share corners with four equivalent Ni(2)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  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. In the second V site, V(2) is bonded to one O(1), one O(10), one O(13), one O(14), one O(5), and one O(9) atom to form VO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(13), one O(14), one O(3), one O(7), and one O(9) atom to form NiO6 octahedra that share corners with four equivalent V(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. In the second Ni site, Ni(2) is bonded to one O(11), one O(12), one O(15), one O(16), one O(4), and one O(8) atom to form NiO6 octahedra that share corners with four equivalent V(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(2), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. In the second P site, P(2) is bonded to one O(1), one O(11), one O(12), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. In the third P site, P(3) is bonded to one O(13), one O(14), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-60°. In the fourth P site, P(4) is bonded to one O(15), one O(16), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-60°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one V(2) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ni(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one V(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one V(2), one Ni(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one V(2), one Ni(1), and one P(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one V(1), one Ni(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one V(1), one Ni(2), and one P(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one P(3) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one V(1), one Ni(2), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one V(1), one Ni(2), and one P(4) atom.
VNi(PO4)2 crystallizes in the triclinic P1 space group. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(11), one O(12), one O(15), one O(16), one O(2), and one O(6) atom to form VO6 octahedra that share corners with four equivalent Ni(2)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  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. The V(1)-O(11) bond length is 1.94 Å. The V(1)-O(12) bond length is 1.96 Å. The V(1)-O(15) bond length is 2.02 Å. The V(1)-O(16) bond length is 2.09 Å. The V(1)-O(2) bond length is 1.96 Å. The V(1)-O(6) bond length is 1.91 Å. In the second V site, V(2) is bonded to one O(1), one O(10), one O(13), one O(14), one O(5), and one O(9) atom to form VO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. The V(2)-O(1) bond length is 1.96 Å. The V(2)-O(10) bond length is 1.95 Å. The V(2)-O(13) bond length is 2.05 Å. The V(2)-O(14) bond length is 2.07 Å. The V(2)-O(5) bond length is 1.92 Å. The V(2)-O(9) bond length is 1.95 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(13), one O(14), one O(3), one O(7), and one O(9) atom to form NiO6 octahedra that share corners with four equivalent V(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. The Ni(1)-O(10) bond length is 2.28 Å. The Ni(1)-O(13) bond length is 2.10 Å. The Ni(1)-O(14) bond length is 2.09 Å. The Ni(1)-O(3) bond length is 1.97 Å. The Ni(1)-O(7) bond length is 1.98 Å. The Ni(1)-O(9) bond length is 2.29 Å. In the second Ni site, Ni(2) is bonded to one O(11), one O(12), one O(15), one O(16), one O(4), and one O(8) atom to form NiO6 octahedra that share corners with four equivalent V(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-52°. The Ni(2)-O(11) bond length is 2.30 Å. The Ni(2)-O(12) bond length is 2.26 Å. The Ni(2)-O(15) bond length is 2.11 Å. The Ni(2)-O(16) bond length is 2.09 Å. The Ni(2)-O(4) bond length is 1.97 Å. The Ni(2)-O(8) bond length is 1.98 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(2), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. The P(1)-O(10) bond length is 1.60 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.50 Å. The P(1)-O(9) bond length is 1.60 Å. In the second P site, P(2) is bonded to one O(1), one O(11), one O(12), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent V(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. The P(2)-O(1) bond length is 1.54 Å. The P(2)-O(11) bond length is 1.60 Å. The P(2)-O(12) bond length is 1.60 Å. The P(2)-O(4) bond length is 1.50 Å. In the third P site, P(3) is bonded to one O(13), one O(14), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one V(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-60°. The P(3)-O(13) bond length is 1.59 Å. The P(3)-O(14) bond length is 1.58 Å. The P(3)-O(5) bond length is 1.55 Å. The P(3)-O(8) bond length is 1.50 Å. In the fourth P site, P(4) is bonded to one O(15), one O(16), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-60°. The P(4)-O(15) bond length is 1.59 Å. The P(4)-O(16) bond length is 1.58 Å. The P(4)-O(6) bond length is 1.54 Å. The P(4)-O(7) bond length is 1.50 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one V(2) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one V(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Ni(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one V(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one V(2), one Ni(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one V(2), one Ni(1), and one P(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one V(1), one Ni(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one V(1), one Ni(2), and one P(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one V(2), one Ni(1), and one P(3) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one V(1), one Ni(2), and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one V(1), one Ni(2), and one P(4) atom.