Pr2Co15Ga2 crystallizes in the trigonal R-3m space group. Pr(1) is bonded in a 19-coordinate geometry to three equivalent Co(1), six equivalent Co(2), nine equivalent Co(3), and one Ga(1) atom. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Pr(1), four equivalent Co(2), four equivalent Co(3), and two equivalent Ga(1) atoms to form distorted CoPr2Ga2Co8 cuboctahedra that share corners with four equivalent Co(1)Pr2Ga2Co8 cuboctahedra, corners with ten equivalent Co(3)Pr3GaCo8 cuboctahedra, edges with six equivalent Co(3)Pr3GaCo8 cuboctahedra, faces with four equivalent Co(1)Pr2Ga2Co8 cuboctahedra, and faces with six equivalent Co(3)Pr3GaCo8 cuboctahedra. In the second Co site, Co(2) is bonded in a distorted q6 geometry to two equivalent Pr(1), two equivalent Co(1), two equivalent Co(2), four equivalent Co(3), and two equivalent Ga(1) atoms. In the third Co site, Co(3) is bonded to three equivalent Pr(1), two equivalent Co(1), two equivalent Co(3), four equivalent Co(2), and one Ga(1) atom to form CoPr3GaCo8 cuboctahedra that share corners with five equivalent Co(1)Pr2Ga2Co8 cuboctahedra, corners with ten equivalent Co(3)Pr3GaCo8 cuboctahedra, edges with three equivalent Co(1)Pr2Ga2Co8 cuboctahedra, edges with five equivalent Co(3)Pr3GaCo8 cuboctahedra, faces with three equivalent Co(1)Pr2Ga2Co8 cuboctahedra, and faces with seven equivalent Co(3)Pr3GaCo8 cuboctahedra. Ga(1) is bonded in a 14-coordinate geometry to one Pr(1), three equivalent Co(1), three equivalent Co(3), six equivalent Co(2), and one Ga(1) atom.
Pr2Co15Ga2 crystallizes in the trigonal R-3m space group. Pr(1) is bonded in a 19-coordinate geometry to three equivalent Co(1), six equivalent Co(2), nine equivalent Co(3), and one Ga(1) atom. All Pr(1)-Co(1) bond lengths are 3.34 Å. All Pr(1)-Co(2) bond lengths are 3.05 Å. There are a spread of Pr(1)-Co(3) bond distances ranging from 2.95-3.21 Å. The Pr(1)-Ga(1) bond length is 3.02 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Pr(1), four equivalent Co(2), four equivalent Co(3), and two equivalent Ga(1) atoms to form distorted CoPr2Ga2Co8 cuboctahedra that share corners with four equivalent Co(1)Pr2Ga2Co8 cuboctahedra, corners with ten equivalent Co(3)Pr3GaCo8 cuboctahedra, edges with six equivalent Co(3)Pr3GaCo8 cuboctahedra, faces with four equivalent Co(1)Pr2Ga2Co8 cuboctahedra, and faces with six equivalent Co(3)Pr3GaCo8 cuboctahedra. All Co(1)-Co(2) bond lengths are 2.41 Å. All Co(1)-Co(3) bond lengths are 2.45 Å. Both Co(1)-Ga(1) bond lengths are 2.55 Å. In the second Co site, Co(2) is bonded in a distorted q6 geometry to two equivalent Pr(1), two equivalent Co(1), two equivalent Co(2), four equivalent Co(3), and two equivalent Ga(1) atoms. Both Co(2)-Co(2) bond lengths are 2.42 Å. There are two shorter (2.57 Å) and two longer (2.60 Å) Co(2)-Co(3) bond lengths. Both Co(2)-Ga(1) bond lengths are 2.75 Å. In the third Co site, Co(3) is bonded to three equivalent Pr(1), two equivalent Co(1), two equivalent Co(3), four equivalent Co(2), and one Ga(1) atom to form CoPr3GaCo8 cuboctahedra that share corners with five equivalent Co(1)Pr2Ga2Co8 cuboctahedra, corners with ten equivalent Co(3)Pr3GaCo8 cuboctahedra, edges with three equivalent Co(1)Pr2Ga2Co8 cuboctahedra, edges with five equivalent Co(3)Pr3GaCo8 cuboctahedra, faces with three equivalent Co(1)Pr2Ga2Co8 cuboctahedra, and faces with seven equivalent Co(3)Pr3GaCo8 cuboctahedra. Both Co(3)-Co(3) bond lengths are 2.48 Å. The Co(3)-Ga(1) bond length is 2.61 Å. Ga(1) is bonded in a 14-coordinate geometry to one Pr(1), three equivalent Co(1), three equivalent Co(3), six equivalent Co(2), and one Ga(1) atom. The Ga(1)-Ga(1) bond length is 2.62 Å.