Pr2PdSi3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Pd(1) and eight equivalent Si(1) atoms to form PrSi8Pd4 cuboctahedra that share edges with four equivalent Pr(2)Si12 cuboctahedra, edges with eight equivalent Pr(1)Si8Pd4 cuboctahedra, faces with two equivalent Pr(2)Si12 cuboctahedra, and faces with six equivalent Pr(1)Si8Pd4 cuboctahedra. In the second Pr site, Pr(2) is bonded to twelve equivalent Si(1) atoms to form PrSi12 cuboctahedra that share edges with twelve equivalent Pr(1)Si8Pd4 cuboctahedra, faces with two equivalent Pr(2)Si12 cuboctahedra, and faces with six equivalent Pr(1)Si8Pd4 cuboctahedra. Pd(1) is bonded in a 9-coordinate geometry to six equivalent Pr(1) and three equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent Pr(2), four equivalent Pr(1), one Pd(1), and two equivalent Si(1) atoms.
Pr2PdSi3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Pd(1) and eight equivalent Si(1) atoms to form PrSi8Pd4 cuboctahedra that share edges with four equivalent Pr(2)Si12 cuboctahedra, edges with eight equivalent Pr(1)Si8Pd4 cuboctahedra, faces with two equivalent Pr(2)Si12 cuboctahedra, and faces with six equivalent Pr(1)Si8Pd4 cuboctahedra. There are two shorter (3.20 Å) and two longer (3.24 Å) Pr(1)-Pd(1) bond lengths. There are four shorter (3.20 Å) and four longer (3.25 Å) Pr(1)-Si(1) bond lengths. In the second Pr site, Pr(2) is bonded to twelve equivalent Si(1) atoms to form PrSi12 cuboctahedra that share edges with twelve equivalent Pr(1)Si8Pd4 cuboctahedra, faces with two equivalent Pr(2)Si12 cuboctahedra, and faces with six equivalent Pr(1)Si8Pd4 cuboctahedra. There are six shorter (3.19 Å) and six longer (3.22 Å) Pr(2)-Si(1) bond lengths. Pd(1) is bonded in a 9-coordinate geometry to six equivalent Pr(1) and three equivalent Si(1) atoms. All Pd(1)-Si(1) bond lengths are 2.41 Å. Si(1) is bonded in a 9-coordinate geometry to two equivalent Pr(2), four equivalent Pr(1), one Pd(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.38 Å.