MgCrPtO2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent O(1) atoms. Cr(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form edge-sharing CrO6 octahedra. Pt(1) is bonded in a 4-coordinate geometry to three equivalent Mg(1) and one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mg(1) and three equivalent Cr(1) atoms to form OMg3Cr3 octahedra that share corners with three equivalent O(2)Cr3Pt tetrahedra, edges with six equivalent O(1)Mg3Cr3 octahedra, and edges with three equivalent O(2)Cr3Pt tetrahedra. In the second O site, O(2) is bonded to three equivalent Cr(1) and one Pt(1) atom to form distorted OCr3Pt tetrahedra that share corners with three equivalent O(1)Mg3Cr3 octahedra, corners with six equivalent O(2)Cr3Pt tetrahedra, and edges with three equivalent O(1)Mg3Cr3 octahedra. The corner-sharing octahedral tilt angles are 8°.
MgCrPtO2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Pt(1) and three equivalent O(1) atoms. All Mg(1)-Pt(1) bond lengths are 2.64 Å. There are two shorter (2.20 Å) and one longer (2.21 Å) Mg(1)-O(1) bond length. Cr(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form edge-sharing CrO6 octahedra. There are two shorter (2.13 Å) and one longer (2.14 Å) Cr(1)-O(1) bond length. All Cr(1)-O(2) bond lengths are 1.95 Å. Pt(1) is bonded in a 4-coordinate geometry to three equivalent Mg(1) and one O(2) atom. The Pt(1)-O(2) bond length is 2.53 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mg(1) and three equivalent Cr(1) atoms to form OMg3Cr3 octahedra that share corners with three equivalent O(2)Cr3Pt tetrahedra, edges with six equivalent O(1)Mg3Cr3 octahedra, and edges with three equivalent O(2)Cr3Pt tetrahedra. In the second O site, O(2) is bonded to three equivalent Cr(1) and one Pt(1) atom to form distorted OCr3Pt tetrahedra that share corners with three equivalent O(1)Mg3Cr3 octahedra, corners with six equivalent O(2)Cr3Pt tetrahedra, and edges with three equivalent O(1)Mg3Cr3 octahedra. The corner-sharing octahedral tilt angles are 8°.