Pr2O3 crystallizes in the trigonal P-3m1 space group. Pr(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Pr(1) atoms to form OPr4 tetrahedra that share corners with six equivalent O(2)Pr6 octahedra, corners with six equivalent O(1)Pr4 tetrahedra, edges with three equivalent O(2)Pr6 octahedra, and edges with three equivalent O(1)Pr4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-56°. In the second O site, O(2) is bonded to six equivalent Pr(1) atoms to form OPr6 octahedra that share corners with twelve equivalent O(1)Pr4 tetrahedra, edges with six equivalent O(2)Pr6 octahedra, and edges with six equivalent O(1)Pr4 tetrahedra.
Pr2O3 crystallizes in the trigonal P-3m1 space group. Pr(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. All Pr(1)-O(2) bond lengths are 2.70 Å. There are three shorter (2.34 Å) and one longer (2.41 Å) Pr(1)-O(1) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Pr(1) atoms to form OPr4 tetrahedra that share corners with six equivalent O(2)Pr6 octahedra, corners with six equivalent O(1)Pr4 tetrahedra, edges with three equivalent O(2)Pr6 octahedra, and edges with three equivalent O(1)Pr4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-56°. In the second O site, O(2) is bonded to six equivalent Pr(1) atoms to form OPr6 octahedra that share corners with twelve equivalent O(1)Pr4 tetrahedra, edges with six equivalent O(2)Pr6 octahedra, and edges with six equivalent O(1)Pr4 tetrahedra.