MgGa5 crystallizes in the hexagonal P-62m space group. Mg(1) is bonded to six Ga(1,1) and six equivalent Ga(2) atoms to form MgGa12 cuboctahedra that share corners with eighteen equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with six equivalent Mg(1)Ga12 cuboctahedra; edges with twelve Ga(1,1)Mg2Ga10 cuboctahedra; faces with two equivalent Mg(1)Ga12 cuboctahedra; faces with six equivalent Ga(2)Mg3Ga9 cuboctahedra; and faces with twelve Ga(1,1)Mg2Ga10 cuboctahedra. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent Mg(1); four equivalent Ga(2); and six Ga(1,1) atoms to form distorted GaMg2Ga10 cuboctahedra that share corners with eighteen Ga(1,1)Mg2Ga10 cuboctahedra; edges with four equivalent Mg(1)Ga12 cuboctahedra; edges with six equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with eight equivalent Ga(2)Mg3Ga9 cuboctahedra; faces with four equivalent Mg(1)Ga12 cuboctahedra; faces with eight Ga(1,1)Mg2Ga10 cuboctahedra; and faces with eight equivalent Ga(2)Mg3Ga9 cuboctahedra. In the second Ga site, Ga(1) is bonded to two equivalent Mg(1), four equivalent Ga(2), and six equivalent Ga(1) atoms to form distorted GaMg2Ga10 cuboctahedra that share corners with eighteen equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with four equivalent Mg(1)Ga12 cuboctahedra; edges with six equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with eight equivalent Ga(2)Mg3Ga9 cuboctahedra; faces with four equivalent Mg(1)Ga12 cuboctahedra; faces with eight Ga(1,1)Mg2Ga10 cuboctahedra; and faces with eight equivalent Ga(2)Mg3Ga9 cuboctahedra. In the third Ga site, Ga(2) is bonded to three equivalent Mg(1); three equivalent Ga(2); and six Ga(1,1) atoms to form distorted GaMg3Ga9 cuboctahedra that share corners with nine equivalent Mg(1)Ga12 cuboctahedra; corners with nine equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with six equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with twelve Ga(1,1)Mg2Ga10 cuboctahedra; faces with three equivalent Mg(1)Ga12 cuboctahedra; faces with five equivalent Ga(2)Mg3Ga9 cuboctahedra; and faces with twelve Ga(1,1)Mg2Ga10 cuboctahedra.
MgGa5 crystallizes in the hexagonal P-62m space group. Mg(1) is bonded to six Ga(1,1) and six equivalent Ga(2) atoms to form MgGa12 cuboctahedra that share corners with eighteen equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with six equivalent Mg(1)Ga12 cuboctahedra; edges with twelve Ga(1,1)Mg2Ga10 cuboctahedra; faces with two equivalent Mg(1)Ga12 cuboctahedra; faces with six equivalent Ga(2)Mg3Ga9 cuboctahedra; and faces with twelve Ga(1,1)Mg2Ga10 cuboctahedra. All Mg(1)-Ga(1,1) bond lengths are 2.99 Å. All Mg(1)-Ga(2) bond lengths are 2.94 Å. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent Mg(1); four equivalent Ga(2); and six Ga(1,1) atoms to form distorted GaMg2Ga10 cuboctahedra that share corners with eighteen Ga(1,1)Mg2Ga10 cuboctahedra; edges with four equivalent Mg(1)Ga12 cuboctahedra; edges with six equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with eight equivalent Ga(2)Mg3Ga9 cuboctahedra; faces with four equivalent Mg(1)Ga12 cuboctahedra; faces with eight Ga(1,1)Mg2Ga10 cuboctahedra; and faces with eight equivalent Ga(2)Mg3Ga9 cuboctahedra. All Ga(1)-Ga(2) bond lengths are 2.95 Å. There are four shorter (2.91 Å) and two longer (3.02 Å) Ga(1)-Ga(1,1) bond lengths. In the second Ga site, Ga(1) is bonded to two equivalent Mg(1), four equivalent Ga(2), and six equivalent Ga(1) atoms to form distorted GaMg2Ga10 cuboctahedra that share corners with eighteen equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with four equivalent Mg(1)Ga12 cuboctahedra; edges with six equivalent Ga(1)Mg2Ga10 cuboctahedra; edges with eight equivalent Ga(2)Mg3Ga9 cuboctahedra; faces with four equivalent Mg(1)Ga12 cuboctahedra; faces with eight Ga(1,1)Mg2Ga10 cuboctahedra; and faces with eight equivalent Ga(2)Mg3Ga9 cuboctahedra. All Ga(1)-Ga(2) bond lengths are 2.95 Å. In the third Ga site, Ga(2) is bonded to three equivalent Mg(1); three equivalent Ga(2); and six Ga(1,1) atoms to form distorted GaMg3Ga9 cuboctahedra that share corners with nine equivalent Mg(1)Ga12 cuboctahedra; corners with nine equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with six equivalent Ga(2)Mg3Ga9 cuboctahedra; edges with twelve Ga(1,1)Mg2Ga10 cuboctahedra; faces with three equivalent Mg(1)Ga12 cuboctahedra; faces with five equivalent Ga(2)Mg3Ga9 cuboctahedra; and faces with twelve Ga(1,1)Mg2Ga10 cuboctahedra. All Ga(2)-Ga(2) bond lengths are 2.94 Å.