Al2MgC2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to six equivalent C(1) atoms to form distorted MgC6 octahedra that share corners with twelve equivalent Al(1)C4 tetrahedra, edges with six equivalent Mg(1)C6 octahedra, and edges with six equivalent Al(1)C4 tetrahedra. Al(1) is bonded to four equivalent C(1) atoms to form distorted AlC4 tetrahedra that share corners with six equivalent Mg(1)C6 octahedra, corners with six equivalent Al(1)C4 tetrahedra, edges with three equivalent Mg(1)C6 octahedra, and edges with three equivalent Al(1)C4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-51°. C(1) is bonded in a 7-coordinate geometry to three equivalent Mg(1) and four equivalent Al(1) atoms.
Al2MgC2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to six equivalent C(1) atoms to form distorted MgC6 octahedra that share corners with twelve equivalent Al(1)C4 tetrahedra, edges with six equivalent Mg(1)C6 octahedra, and edges with six equivalent Al(1)C4 tetrahedra. All Mg(1)-C(1) bond lengths are 2.51 Å. Al(1) is bonded to four equivalent C(1) atoms to form distorted AlC4 tetrahedra that share corners with six equivalent Mg(1)C6 octahedra, corners with six equivalent Al(1)C4 tetrahedra, edges with three equivalent Mg(1)C6 octahedra, and edges with three equivalent Al(1)C4 tetrahedra. The corner-sharing octahedral tilt angles range from 25-51°. There are three shorter (2.01 Å) and one longer (2.21 Å) Al(1)-C(1) bond length. C(1) is bonded in a 7-coordinate geometry to three equivalent Mg(1) and four equivalent Al(1) atoms.