MgNi2(PO4)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(3) and two equivalent O(4) atoms. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), two equivalent Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom.
MgNi2(PO4)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(3) and two equivalent O(4) atoms. Both Mg(1)-O(3) bond lengths are 2.11 Å. Both Mg(1)-O(4) bond lengths are 1.98 Å. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. The Ni(1)-O(1) bond length is 1.99 Å. The Ni(1)-O(4) bond length is 2.07 Å. Both Ni(1)-O(2) bond lengths are 2.07 Å. Both Ni(1)-O(3) bond lengths are 2.24 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both P(1)-O(2) bond lengths are 1.55 Å. Both P(1)-O(4) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. Both P(2)-O(1) bond lengths are 1.51 Å. Both P(2)-O(3) bond lengths are 1.61 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), two equivalent Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom.