Pr2Co7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to three equivalent Co(3) and nine equivalent Co(1) atoms. In the second Pr site, Pr(2) is bonded in a 18-coordinate geometry to three equivalent Co(4), three equivalent Co(5), six equivalent Co(1), and six equivalent Co(2) atoms. There are five inequivalent Co sites. In the first Co site, Co(5) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Co(1), and three equivalent Co(2) atoms. In the second Co site, Co(1) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Co(3), one Co(4), one Co(5), and four equivalent Co(1) atoms to form distorted CoPr5Co7 cuboctahedra that share corners with two equivalent Co(3)Pr6Co6 cuboctahedra, corners with six equivalent Co(2)Pr4Co8 cuboctahedra, corners with nine equivalent Co(1)Pr5Co7 cuboctahedra, edges with four equivalent Co(2)Pr4Co8 cuboctahedra, edges with four equivalent Co(1)Pr5Co7 cuboctahedra,  a faceface with one Co(2)Pr4Co8 cuboctahedra, faces with three equivalent Co(3)Pr6Co6 cuboctahedra, and faces with ten equivalent Co(1)Pr5Co7 cuboctahedra. In the third Co site, Co(2) is bonded to four equivalent Pr(2), two equivalent Co(4), two equivalent Co(5), and four equivalent Co(2) atoms to form CoPr4Co8 cuboctahedra that share corners with four equivalent Co(2)Pr4Co8 cuboctahedra, corners with twelve equivalent Co(1)Pr5Co7 cuboctahedra, edges with two equivalent Co(2)Pr4Co8 cuboctahedra, edges with eight equivalent Co(1)Pr5Co7 cuboctahedra, faces with two equivalent Co(1)Pr5Co7 cuboctahedra, and faces with eight equivalent Co(2)Pr4Co8 cuboctahedra. In the fourth Co site, Co(3) is bonded to six equivalent Pr(1) and six equivalent Co(1) atoms to form CoPr6Co6 cuboctahedra that share corners with twelve equivalent Co(1)Pr5Co7 cuboctahedra, edges with six equivalent Co(3)Pr6Co6 cuboctahedra, and faces with eighteen equivalent Co(1)Pr5Co7 cuboctahedra. In the fifth Co site, Co(4) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Co(1), and three equivalent Co(2) atoms.
Pr2Co7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to three equivalent Co(3) and nine equivalent Co(1) atoms. All Pr(1)-Co(3) bond lengths are 3.00 Å. There are six shorter (2.94 Å) and three longer (3.20 Å) Pr(1)-Co(1) bond lengths. In the second Pr site, Pr(2) is bonded in a 18-coordinate geometry to three equivalent Co(4), three equivalent Co(5), six equivalent Co(1), and six equivalent Co(2) atoms. All Pr(2)-Co(4) bond lengths are 2.93 Å. All Pr(2)-Co(5) bond lengths are 2.93 Å. All Pr(2)-Co(1) bond lengths are 3.26 Å. All Pr(2)-Co(2) bond lengths are 3.16 Å. There are five inequivalent Co sites. In the first Co site, Co(5) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Co(1), and three equivalent Co(2) atoms. All Co(5)-Co(1) bond lengths are 2.45 Å. All Co(5)-Co(2) bond lengths are 2.47 Å. In the second Co site, Co(1) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Co(3), one Co(4), one Co(5), and four equivalent Co(1) atoms to form distorted CoPr5Co7 cuboctahedra that share corners with two equivalent Co(3)Pr6Co6 cuboctahedra, corners with six equivalent Co(2)Pr4Co8 cuboctahedra, corners with nine equivalent Co(1)Pr5Co7 cuboctahedra, edges with four equivalent Co(2)Pr4Co8 cuboctahedra, edges with four equivalent Co(1)Pr5Co7 cuboctahedra,  a faceface with one Co(2)Pr4Co8 cuboctahedra, faces with three equivalent Co(3)Pr6Co6 cuboctahedra, and faces with ten equivalent Co(1)Pr5Co7 cuboctahedra. The Co(1)-Co(3) bond length is 2.61 Å. The Co(1)-Co(4) bond length is 2.43 Å. There are two shorter (2.52 Å) and two longer (2.55 Å) Co(1)-Co(1) bond lengths. In the third Co site, Co(2) is bonded to four equivalent Pr(2), two equivalent Co(4), two equivalent Co(5), and four equivalent Co(2) atoms to form CoPr4Co8 cuboctahedra that share corners with four equivalent Co(2)Pr4Co8 cuboctahedra, corners with twelve equivalent Co(1)Pr5Co7 cuboctahedra, edges with two equivalent Co(2)Pr4Co8 cuboctahedra, edges with eight equivalent Co(1)Pr5Co7 cuboctahedra, faces with two equivalent Co(1)Pr5Co7 cuboctahedra, and faces with eight equivalent Co(2)Pr4Co8 cuboctahedra. Both Co(2)-Co(4) bond lengths are 2.48 Å. There are two shorter (2.52 Å) and two longer (2.55 Å) Co(2)-Co(2) bond lengths. In the fourth Co site, Co(3) is bonded to six equivalent Pr(1) and six equivalent Co(1) atoms to form CoPr6Co6 cuboctahedra that share corners with twelve equivalent Co(1)Pr5Co7 cuboctahedra, edges with six equivalent Co(3)Pr6Co6 cuboctahedra, and faces with eighteen equivalent Co(1)Pr5Co7 cuboctahedra. In the fifth Co site, Co(4) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Co(1), and three equivalent Co(2) atoms.