Mg(Rh3As2)2 crystallizes in the hexagonal P-6m2 space group. Mg(1) is bonded to six equivalent Rh(1) and six equivalent As(1) atoms to form face-sharing MgAs6Rh6 cuboctahedra. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1), two equivalent As(1), and two equivalent As(2) atoms. In the second Rh site, Rh(2) is bonded in a 5-coordinate geometry to one As(2) and four equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Rh(1), and four equivalent Rh(2) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to three equivalent Rh(2) and six equivalent Rh(1) atoms.
Mg(Rh3As2)2 crystallizes in the hexagonal P-6m2 space group. Mg(1) is bonded to six equivalent Rh(1) and six equivalent As(1) atoms to form face-sharing MgAs6Rh6 cuboctahedra. All Mg(1)-Rh(1) bond lengths are 3.05 Å. All Mg(1)-As(1) bond lengths are 2.98 Å. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1), two equivalent As(1), and two equivalent As(2) atoms. Both Rh(1)-As(1) bond lengths are 2.40 Å. Both Rh(1)-As(2) bond lengths are 2.53 Å. In the second Rh site, Rh(2) is bonded in a 5-coordinate geometry to one As(2) and four equivalent As(1) atoms. The Rh(2)-As(2) bond length is 2.54 Å. All Rh(2)-As(1) bond lengths are 2.54 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Rh(1), and four equivalent Rh(2) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to three equivalent Rh(2) and six equivalent Rh(1) atoms.