PrMnSi2 crystallizes in the orthorhombic Cmcm space group. Pr(1) is bonded in a 14-coordinate geometry to four equivalent Mn(1), four equivalent Si(1), and six equivalent Si(2) atoms. Mn(1) is bonded to four equivalent Pr(1) and four equivalent Si(1) atoms to form a mixture of distorted edge and face-sharing MnPr4Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Pr(1), four equivalent Mn(1), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to six equivalent Pr(1), one Si(1), and two equivalent Si(2) atoms.
PrMnSi2 crystallizes in the orthorhombic Cmcm space group. Pr(1) is bonded in a 14-coordinate geometry to four equivalent Mn(1), four equivalent Si(1), and six equivalent Si(2) atoms. There are two shorter (3.28 Å) and two longer (3.32 Å) Pr(1)-Mn(1) bond lengths. All Pr(1)-Si(1) bond lengths are 3.16 Å. There are four shorter (3.08 Å) and two longer (3.19 Å) Pr(1)-Si(2) bond lengths. Mn(1) is bonded to four equivalent Pr(1) and four equivalent Si(1) atoms to form a mixture of distorted edge and face-sharing MnPr4Si4 tetrahedra. There are two shorter (2.36 Å) and two longer (2.40 Å) Mn(1)-Si(1) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Pr(1), four equivalent Mn(1), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.51 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to six equivalent Pr(1), one Si(1), and two equivalent Si(2) atoms. Both Si(2)-Si(2) bond lengths are 2.38 Å.