Pr3Si2C2 crystallizes in the orthorhombic Cmm2 space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to six equivalent Si(1) and two equivalent C(1) atoms. In the second Pr site, Pr(2) is bonded to two equivalent Si(1) and four equivalent C(1) atoms to form distorted PrSi2C4 octahedra that share corners with four equivalent C(1)Pr4C trigonal bipyramids and edges with two equivalent Pr(2)Si2C4 octahedra. Si(1) is bonded in a 9-coordinate geometry to one Pr(2), six equivalent Pr(1), and two equivalent Si(1) atoms. C(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one C(1) atom to form distorted CPr4C trigonal bipyramids that share corners with two equivalent Pr(2)Si2C4 octahedra, corners with four equivalent C(1)Pr4C trigonal bipyramids, and edges with two equivalent C(1)Pr4C trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°.
Pr3Si2C2 crystallizes in the orthorhombic Cmm2 space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to six equivalent Si(1) and two equivalent C(1) atoms. There are four shorter (3.11 Å) and two longer (3.15 Å) Pr(1)-Si(1) bond lengths. Both Pr(1)-C(1) bond lengths are 2.72 Å. In the second Pr site, Pr(2) is bonded to two equivalent Si(1) and four equivalent C(1) atoms to form distorted PrSi2C4 octahedra that share corners with four equivalent C(1)Pr4C trigonal bipyramids and edges with two equivalent Pr(2)Si2C4 octahedra. Both Pr(2)-Si(1) bond lengths are 3.40 Å. All Pr(2)-C(1) bond lengths are 2.60 Å. Si(1) is bonded in a 9-coordinate geometry to one Pr(2), six equivalent Pr(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.66 Å. C(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), and one C(1) atom to form distorted CPr4C trigonal bipyramids that share corners with two equivalent Pr(2)Si2C4 octahedra, corners with four equivalent C(1)Pr4C trigonal bipyramids, and edges with two equivalent C(1)Pr4C trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. The C(1)-C(1) bond length is 1.28 Å.