MgCa crystallizes in the trigonal P-3m1 space group. Ca(1) is bonded to nine equivalent Ca(1) and three equivalent Mg(1) atoms to form a mixture of distorted edge, face, and corner-sharing CaCa9Mg3 cuboctahedra. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Ca(1) and three equivalent Mg(1) atoms.
MgCa crystallizes in the trigonal P-3m1 space group. Ca(1) is bonded to nine equivalent Ca(1) and three equivalent Mg(1) atoms to form a mixture of distorted edge, face, and corner-sharing CaCa9Mg3 cuboctahedra. There are six shorter (3.64 Å) and three longer (3.86 Å) Ca(1)-Ca(1) bond lengths. All Ca(1)-Mg(1) bond lengths are 3.48 Å. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Ca(1) and three equivalent Mg(1) atoms. All Mg(1)-Mg(1) bond lengths are 3.30 Å.