MgCrGaO4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra, corners with two equivalent Ga(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O5 trigonal bipyramids, and faces with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. Cr(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with six equivalent Ga(1)O5 trigonal bipyramids, edges with two equivalent Cr(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. Ga(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted GaO5 trigonal bipyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with six equivalent Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ga(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-73°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(1), and two equivalent Ga(1) atoms to form distorted OMgCrGa2 tetrahedra that share corners with two equivalent O(1)MgCrGa2 tetrahedra, corners with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids, and edges with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Ga(1) atom to form distorted OMg2Cr2Ga trigonal bipyramids that share corners with two equivalent O(1)MgCrGa2 tetrahedra, edges with two equivalent O(1)MgCrGa2 tetrahedra, and edges with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms.
MgCrGaO4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra, corners with two equivalent Ga(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ga(1)O5 trigonal bipyramids, and faces with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. The Mg(1)-O(1) bond length is 2.00 Å. The Mg(1)-O(3) bond length is 2.09 Å. Both Mg(1)-O(2) bond lengths are 2.21 Å. Both Mg(1)-O(4) bond lengths are 2.05 Å. Cr(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with six equivalent Ga(1)O5 trigonal bipyramids, edges with two equivalent Cr(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-47°. The Cr(1)-O(1) bond length is 2.08 Å. The Cr(1)-O(3) bond length is 2.07 Å. Both Cr(1)-O(2) bond lengths are 2.11 Å. Both Cr(1)-O(4) bond lengths are 2.00 Å. Ga(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted GaO5 trigonal bipyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with six equivalent Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Ga(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-73°. The Ga(1)-O(2) bond length is 2.01 Å. Both Ga(1)-O(1) bond lengths are 1.97 Å. Both Ga(1)-O(3) bond lengths are 1.97 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(1), and two equivalent Ga(1) atoms to form distorted OMgCrGa2 tetrahedra that share corners with two equivalent O(1)MgCrGa2 tetrahedra, corners with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids, and edges with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Ga(1) atom to form distorted OMg2Cr2Ga trigonal bipyramids that share corners with two equivalent O(1)MgCrGa2 tetrahedra, edges with two equivalent O(1)MgCrGa2 tetrahedra, and edges with two equivalent O(2)Mg2Cr2Ga trigonal bipyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms.