Pr2Mn17C2 crystallizes in the monoclinic C2/m space group. Pr(1) is bonded in a distorted bent 120 degrees geometry to one Mn(7), two equivalent Mn(1), two equivalent Mn(4), three equivalent Mn(6), and two equivalent C(1) atoms. There are seven inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Pr(1), two equivalent Mn(2), two equivalent Mn(4), two equivalent Mn(5), two equivalent Mn(6), and two equivalent Mn(7) atoms to form distorted MnPr2Mn10 cuboctahedra that share corners with two equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with four equivalent C(1)Pr2Mn4 octahedra,  an edgeedge with one Mn(1)Pr2Mn10 cuboctahedra, edges with two equivalent Mn(4)Pr2Mn10 cuboctahedra, edges with two equivalent C(1)Pr2Mn4 octahedra,  a faceface with one Mn(1)Pr2Mn10 cuboctahedra, and faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles range from 21-27°. In the second Mn site, Mn(2) is bonded in a single-bond geometry to one Mn(1), one Mn(3), one Mn(4), one Mn(6), two equivalent Mn(7), and one C(1) atom. In the third Mn site, Mn(3) is bonded in a 10-coordinate geometry to two equivalent Mn(7), four equivalent Mn(2), and four equivalent Mn(5) atoms. In the fourth Mn site, Mn(4) is bonded to two equivalent Pr(1), two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(5), two equivalent Mn(6), and two equivalent Mn(7) atoms to form distorted MnPr2Mn10 cuboctahedra that share corners with two equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with two equivalent C(1)Pr2Mn4 octahedra, edges with two equivalent Mn(1)Pr2Mn10 cuboctahedra, faces with two equivalent Mn(1)Pr2Mn10 cuboctahedra, faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra, and faces with two equivalent C(1)Pr2Mn4 octahedra. The corner-sharing octahedral tilt angles are 49°. In the fifth Mn site, Mn(5) is bonded in a single-bond geometry to one Mn(1), one Mn(3), one Mn(4), one Mn(6), one Mn(7), and one C(1) atom. In the sixth Mn site, Mn(6) is bonded in a 12-coordinate geometry to three equivalent Pr(1), one Mn(7), two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(4), and two equivalent Mn(5) atoms. In the seventh Mn site, Mn(7) is bonded in a 14-coordinate geometry to one Pr(1), one Mn(3), one Mn(6), one Mn(7), two equivalent Mn(1), two equivalent Mn(4), two equivalent Mn(5), and four equivalent Mn(2) atoms. C(1) is bonded to two equivalent Pr(1), two equivalent Mn(2), and two equivalent Mn(5) atoms to form CPr2Mn4 octahedra that share corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with four equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent C(1)Pr2Mn4 octahedra, edges with two equivalent Mn(1)Pr2Mn10 cuboctahedra, and faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 64°.
Pr2Mn17C2 crystallizes in the monoclinic C2/m space group. Pr(1) is bonded in a distorted bent 120 degrees geometry to one Mn(7), two equivalent Mn(1), two equivalent Mn(4), three equivalent Mn(6), and two equivalent C(1) atoms. The Pr(1)-Mn(7) bond length is 3.21 Å. Both Pr(1)-Mn(1) bond lengths are 3.17 Å. Both Pr(1)-Mn(4) bond lengths are 3.38 Å. There are a spread of Pr(1)-Mn(6) bond distances ranging from 3.00-3.42 Å. Both Pr(1)-C(1) bond lengths are 2.57 Å. There are seven inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Pr(1), two equivalent Mn(2), two equivalent Mn(4), two equivalent Mn(5), two equivalent Mn(6), and two equivalent Mn(7) atoms to form distorted MnPr2Mn10 cuboctahedra that share corners with two equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with four equivalent C(1)Pr2Mn4 octahedra,  an edgeedge with one Mn(1)Pr2Mn10 cuboctahedra, edges with two equivalent Mn(4)Pr2Mn10 cuboctahedra, edges with two equivalent C(1)Pr2Mn4 octahedra,  a faceface with one Mn(1)Pr2Mn10 cuboctahedra, and faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles range from 21-27°. Both Mn(1)-Mn(2) bond lengths are 2.40 Å. Both Mn(1)-Mn(4) bond lengths are 2.41 Å. Both Mn(1)-Mn(5) bond lengths are 2.54 Å. Both Mn(1)-Mn(6) bond lengths are 2.75 Å. Both Mn(1)-Mn(7) bond lengths are 2.60 Å. In the second Mn site, Mn(2) is bonded in a single-bond geometry to one Mn(1), one Mn(3), one Mn(4), one Mn(6), two equivalent Mn(7), and one C(1) atom. The Mn(2)-Mn(3) bond length is 2.45 Å. The Mn(2)-Mn(4) bond length is 2.42 Å. The Mn(2)-Mn(6) bond length is 2.57 Å. There is one shorter (2.69 Å) and one longer (2.71 Å) Mn(2)-Mn(7) bond length. The Mn(2)-C(1) bond length is 1.90 Å. In the third Mn site, Mn(3) is bonded in a 10-coordinate geometry to two equivalent Mn(7), four equivalent Mn(2), and four equivalent Mn(5) atoms. Both Mn(3)-Mn(7) bond lengths are 2.65 Å. All Mn(3)-Mn(5) bond lengths are 2.43 Å. In the fourth Mn site, Mn(4) is bonded to two equivalent Pr(1), two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(5), two equivalent Mn(6), and two equivalent Mn(7) atoms to form distorted MnPr2Mn10 cuboctahedra that share corners with two equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with two equivalent C(1)Pr2Mn4 octahedra, edges with two equivalent Mn(1)Pr2Mn10 cuboctahedra, faces with two equivalent Mn(1)Pr2Mn10 cuboctahedra, faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra, and faces with two equivalent C(1)Pr2Mn4 octahedra. The corner-sharing octahedral tilt angles are 49°. Both Mn(4)-Mn(5) bond lengths are 2.42 Å. Both Mn(4)-Mn(6) bond lengths are 2.46 Å. Both Mn(4)-Mn(7) bond lengths are 2.67 Å. In the fifth Mn site, Mn(5) is bonded in a single-bond geometry to one Mn(1), one Mn(3), one Mn(4), one Mn(6), one Mn(7), and one C(1) atom. The Mn(5)-Mn(6) bond length is 2.71 Å. The Mn(5)-Mn(7) bond length is 2.58 Å. The Mn(5)-C(1) bond length is 1.91 Å. In the sixth Mn site, Mn(6) is bonded in a 12-coordinate geometry to three equivalent Pr(1), one Mn(7), two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(4), and two equivalent Mn(5) atoms. The Mn(6)-Mn(7) bond length is 2.61 Å. In the seventh Mn site, Mn(7) is bonded in a 14-coordinate geometry to one Pr(1), one Mn(3), one Mn(6), one Mn(7), two equivalent Mn(1), two equivalent Mn(4), two equivalent Mn(5), and four equivalent Mn(2) atoms. The Mn(7)-Mn(7) bond length is 2.33 Å. C(1) is bonded to two equivalent Pr(1), two equivalent Mn(2), and two equivalent Mn(5) atoms to form CPr2Mn4 octahedra that share corners with two equivalent Mn(4)Pr2Mn10 cuboctahedra, corners with four equivalent Mn(1)Pr2Mn10 cuboctahedra, corners with two equivalent C(1)Pr2Mn4 octahedra, edges with two equivalent Mn(1)Pr2Mn10 cuboctahedra, and faces with two equivalent Mn(4)Pr2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 64°.