PrMnNi4 crystallizes in the hexagonal P-6m2 space group. Pr(1) is bonded in a 18-coordinate geometry to three equivalent Mn(1), three equivalent Ni(1), and twelve equivalent Ni(2) atoms. Mn(1) is bonded to three equivalent Pr(1), three equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted MnPr3Ni9 cuboctahedra that share corners with nine equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, corners with twelve equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with six equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with two equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with three equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, and faces with eighteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Pr(1), three equivalent Mn(1), and six equivalent Ni(2) atoms to form NiPr3Mn3Ni6 cuboctahedra that share corners with nine equivalent Mn(1)Pr3Ni9 cuboctahedra, corners with twelve equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with six equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, faces with two equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, faces with three equivalent Mn(1)Pr3Ni9 cuboctahedra, and faces with eighteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to four equivalent Pr(1), two equivalent Mn(1), two equivalent Ni(1), and four equivalent Ni(2) atoms to form distorted NiPr4Mn2Ni6 cuboctahedra that share corners with four equivalent Mn(1)Pr3Ni9 cuboctahedra, corners with four equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, corners with sixteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with ten equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, faces with six equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with six equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, and faces with ten equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra.
PrMnNi4 crystallizes in the hexagonal P-6m2 space group. Pr(1) is bonded in a 18-coordinate geometry to three equivalent Mn(1), three equivalent Ni(1), and twelve equivalent Ni(2) atoms. All Pr(1)-Mn(1) bond lengths are 2.91 Å. All Pr(1)-Ni(1) bond lengths are 2.91 Å. All Pr(1)-Ni(2) bond lengths are 3.21 Å. Mn(1) is bonded to three equivalent Pr(1), three equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted MnPr3Ni9 cuboctahedra that share corners with nine equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, corners with twelve equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with six equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with two equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with three equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, and faces with eighteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra. All Mn(1)-Ni(1) bond lengths are 2.91 Å. All Mn(1)-Ni(2) bond lengths are 2.47 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Pr(1), three equivalent Mn(1), and six equivalent Ni(2) atoms to form NiPr3Mn3Ni6 cuboctahedra that share corners with nine equivalent Mn(1)Pr3Ni9 cuboctahedra, corners with twelve equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with six equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, faces with two equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, faces with three equivalent Mn(1)Pr3Ni9 cuboctahedra, and faces with eighteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.46 Å. In the second Ni site, Ni(2) is bonded to four equivalent Pr(1), two equivalent Mn(1), two equivalent Ni(1), and four equivalent Ni(2) atoms to form distorted NiPr4Mn2Ni6 cuboctahedra that share corners with four equivalent Mn(1)Pr3Ni9 cuboctahedra, corners with four equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, corners with sixteen equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, edges with ten equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra, faces with six equivalent Mn(1)Pr3Ni9 cuboctahedra, faces with six equivalent Ni(1)Pr3Mn3Ni6 cuboctahedra, and faces with ten equivalent Ni(2)Pr4Mn2Ni6 cuboctahedra. There are two shorter (2.50 Å) and two longer (2.55 Å) Ni(2)-Ni(2) bond lengths.