CaNi2(P2O7)2 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(14), one O(3), one O(6), one O(7), and one O(9) atom. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(11), one O(12), one O(14), one O(3), one O(5), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one Ni(2)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(11), one O(12), one O(13), one O(4), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Ni(1)O6 octahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(12), one O(2), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-61°. In the second P site, P(2) is bonded to one O(1), one O(11), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-57°. In the third P site, P(3) is bonded to one O(1), one O(14), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. In the fourth P site, P(4) is bonded to one O(13), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-50°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(2) and one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(1) and one P(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ni(2), and one P(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(2), and one P(4) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Ca(1), one Ni(1), one Ni(2), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(3) atom.
CaNi2(P2O7)2 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(14), one O(3), one O(6), one O(7), and one O(9) atom. The Ca(1)-O(10) bond length is 2.23 Å. The Ca(1)-O(12) bond length is 2.74 Å. The Ca(1)-O(14) bond length is 2.68 Å. The Ca(1)-O(3) bond length is 2.38 Å. The Ca(1)-O(6) bond length is 2.49 Å. The Ca(1)-O(7) bond length is 2.73 Å. The Ca(1)-O(9) bond length is 2.30 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(11), one O(12), one O(14), one O(3), one O(5), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  an edgeedge with one Ni(2)O6 octahedra. The Ni(1)-O(11) bond length is 2.09 Å. The Ni(1)-O(12) bond length is 2.14 Å. The Ni(1)-O(14) bond length is 2.19 Å. The Ni(1)-O(3) bond length is 2.06 Å. The Ni(1)-O(5) bond length is 2.03 Å. The Ni(1)-O(8) bond length is 2.07 Å. In the second Ni site, Ni(2) is bonded to one O(11), one O(12), one O(13), one O(4), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Ni(1)O6 octahedra. The Ni(2)-O(11) bond length is 2.12 Å. The Ni(2)-O(12) bond length is 2.14 Å. The Ni(2)-O(13) bond length is 2.05 Å. The Ni(2)-O(4) bond length is 2.05 Å. The Ni(2)-O(6) bond length is 2.11 Å. The Ni(2)-O(7) bond length is 2.13 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(12), one O(2), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-61°. The P(1)-O(10) bond length is 1.50 Å. The P(1)-O(12) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.61 Å. The P(1)-O(3) bond length is 1.53 Å. In the second P site, P(2) is bonded to one O(1), one O(11), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-57°. The P(2)-O(1) bond length is 1.60 Å. The P(2)-O(11) bond length is 1.55 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(9) bond length is 1.53 Å. In the third P site, P(3) is bonded to one O(1), one O(14), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. The P(3)-O(1) bond length is 1.61 Å. The P(3)-O(14) bond length is 1.53 Å. The P(3)-O(6) bond length is 1.55 Å. The P(3)-O(8) bond length is 1.52 Å. In the fourth P site, P(4) is bonded to one O(13), one O(2), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-50°. The P(4)-O(13) bond length is 1.52 Å. The P(4)-O(2) bond length is 1.61 Å. The P(4)-O(5) bond length is 1.54 Å. The P(4)-O(7) bond length is 1.53 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one P(2) and one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one P(1) and one P(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ni(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ni(2), and one P(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(2), and one P(4) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one P(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Ca(1), one Ni(1), one Ni(2), and one P(1) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(3) atom.