Pr2Mo2C3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 5-coordinate geometry to one C(2), two equivalent C(1), and two equivalent C(3) atoms. In the second Pr site, Pr(2) is bonded in a 5-coordinate geometry to one C(3), two equivalent C(1), and two equivalent C(2) atoms. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one C(1), one C(3), and two equivalent C(2) atoms to form a mixture of edge and corner-sharing MoC4 trigonal pyramids. In the second Mo site, Mo(2) is bonded to one C(1), one C(2), and two equivalent C(3) atoms to form a mixture of distorted edge and corner-sharing MoC4 trigonal pyramids. There are three inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), one Mo(1), and one Mo(2) atom to form CPr4Mo2 octahedra that share corners with two equivalent C(1)Pr4Mo2 octahedra, corners with six equivalent C(3)Pr3Mo3 octahedra,  an edgeedge with one C(1)Pr4Mo2 octahedra, and  a faceface with one C(3)Pr3Mo3 octahedra. The corner-sharing octahedral tilt angles range from 38-79°. In the second C site, C(2) is bonded in a 6-coordinate geometry to one Pr(1), two equivalent Pr(2), one Mo(2), and two equivalent Mo(1) atoms. In the third C site, C(3) is bonded to one Pr(2), two equivalent Pr(1), one Mo(1), and two equivalent Mo(2) atoms to form CPr3Mo3 octahedra that share corners with six equivalent C(1)Pr4Mo2 octahedra, edges with two equivalent C(3)Pr3Mo3 octahedra, and  a faceface with one C(1)Pr4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 38-64°.
Pr2Mo2C3 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 5-coordinate geometry to one C(2), two equivalent C(1), and two equivalent C(3) atoms. The Pr(1)-C(2) bond length is 2.94 Å. There is one shorter (2.66 Å) and one longer (2.74 Å) Pr(1)-C(1) bond length. There is one shorter (2.71 Å) and one longer (2.74 Å) Pr(1)-C(3) bond length. In the second Pr site, Pr(2) is bonded in a 5-coordinate geometry to one C(3), two equivalent C(1), and two equivalent C(2) atoms. The Pr(2)-C(3) bond length is 2.64 Å. There is one shorter (2.67 Å) and one longer (2.83 Å) Pr(2)-C(1) bond length. There is one shorter (2.59 Å) and one longer (2.75 Å) Pr(2)-C(2) bond length. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one C(1), one C(3), and two equivalent C(2) atoms to form a mixture of edge and corner-sharing MoC4 trigonal pyramids. The Mo(1)-C(1) bond length is 1.98 Å. The Mo(1)-C(3) bond length is 2.10 Å. Both Mo(1)-C(2) bond lengths are 2.09 Å. In the second Mo site, Mo(2) is bonded to one C(1), one C(2), and two equivalent C(3) atoms to form a mixture of distorted edge and corner-sharing MoC4 trigonal pyramids. The Mo(2)-C(1) bond length is 2.08 Å. The Mo(2)-C(2) bond length is 2.15 Å. There is one shorter (2.05 Å) and one longer (2.11 Å) Mo(2)-C(3) bond length. There are three inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), one Mo(1), and one Mo(2) atom to form CPr4Mo2 octahedra that share corners with two equivalent C(1)Pr4Mo2 octahedra, corners with six equivalent C(3)Pr3Mo3 octahedra,  an edgeedge with one C(1)Pr4Mo2 octahedra, and  a faceface with one C(3)Pr3Mo3 octahedra. The corner-sharing octahedral tilt angles range from 38-79°. In the second C site, C(2) is bonded in a 6-coordinate geometry to one Pr(1), two equivalent Pr(2), one Mo(2), and two equivalent Mo(1) atoms. In the third C site, C(3) is bonded to one Pr(2), two equivalent Pr(1), one Mo(1), and two equivalent Mo(2) atoms to form CPr3Mo3 octahedra that share corners with six equivalent C(1)Pr4Mo2 octahedra, edges with two equivalent C(3)Pr3Mo3 octahedra, and  a faceface with one C(1)Pr4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 38-64°.