Pr2Co15Al2 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 Al(1) atom. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to two equivalent Pr(1), four equivalent Co(2), four equivalent Co(3), and two equivalent Al(1) atoms. 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 Al(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 Al(1) atom to form a mixture of distorted face, corner, and edge-sharing CoPr3AlCo8 cuboctahedra. Al(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 Al(1) atom.
Pr2Co15Al2 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 Al(1) atom. All Pr(1)-Co(1) bond lengths are 3.34 Å. All Pr(1)-Co(2) bond lengths are 3.04 Å. There are a spread of Pr(1)-Co(3) bond distances ranging from 2.96-3.19 Å. The Pr(1)-Al(1) bond length is 3.06 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to two equivalent Pr(1), four equivalent Co(2), four equivalent Co(3), and two equivalent Al(1) atoms. All Co(1)-Co(2) bond lengths are 2.41 Å. All Co(1)-Co(3) bond lengths are 2.42 Å. Both Co(1)-Al(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 Al(1) atoms. Both Co(2)-Co(2) bond lengths are 2.38 Å. There are two shorter (2.57 Å) and two longer (2.61 Å) Co(2)-Co(3) bond lengths. Both Co(2)-Al(1) bond lengths are 2.71 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 Al(1) atom to form a mixture of distorted face, corner, and edge-sharing CoPr3AlCo8 cuboctahedra. Both Co(3)-Co(3) bond lengths are 2.49 Å. The Co(3)-Al(1) bond length is 2.58 Å. Al(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 Al(1) atom. The Al(1)-Al(1) bond length is 2.60 Å.