MgNi2O5 crystallizes in the orthorhombic Pmmn space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Ni(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing NiO5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and two equivalent Ni(1) atoms to form corner-sharing OMg2Ni2 tetrahedra. In the second O site, O(2) is bonded in a see-saw-like geometry to one Mg(1) and three equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Ni(1), and one O(3) atom.
MgNi2O5 crystallizes in the orthorhombic Pmmn space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Mg(1)-O(1) bond lengths are 2.06 Å. Both Mg(1)-O(2) bond lengths are 2.41 Å. All Mg(1)-O(3) bond lengths are 2.17 Å. Ni(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing NiO5 trigonal bipyramids. The Ni(1)-O(1) bond length is 1.83 Å. The Ni(1)-O(3) bond length is 1.95 Å. There is one shorter (1.86 Å) and two longer (1.97 Å) Ni(1)-O(2) bond lengths. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and two equivalent Ni(1) atoms to form corner-sharing OMg2Ni2 tetrahedra. In the second O site, O(2) is bonded in a see-saw-like geometry to one Mg(1) and three equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Ni(1), and one O(3) atom. The O(3)-O(3) bond length is 1.51 Å.