Pr3IrO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Pr site, Pr(2) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted PrO7 pentagonal bipyramids that share corners with two equivalent Ir(1)O6 octahedra, corners with three equivalent Pr(2)O7 pentagonal bipyramids, edges with two equivalent Ir(1)O6 octahedra, and edges with two equivalent Pr(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. Ir(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form IrO6 octahedra that share corners with two equivalent Ir(1)O6 octahedra, corners with four equivalent Pr(2)O7 pentagonal bipyramids, and edges with four equivalent Pr(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Pr(2) and two equivalent Ir(1) atoms to form distorted OPr2Ir2 trigonal pyramids that share corners with four equivalent O(2)Pr4 tetrahedra and corners with two equivalent O(1)Pr2Ir2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form OPr4 tetrahedra that share corners with six equivalent O(2)Pr4 tetrahedra, corners with two equivalent O(1)Pr2Ir2 trigonal pyramids, and  an edgeedge with one O(2)Pr4 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Pr(2), and one Ir(1) atom.
Pr3IrO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. All Pr(1)-O(2) bond lengths are 2.40 Å. All Pr(1)-O(3) bond lengths are 2.76 Å. In the second Pr site, Pr(2) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted PrO7 pentagonal bipyramids that share corners with two equivalent Ir(1)O6 octahedra, corners with three equivalent Pr(2)O7 pentagonal bipyramids, edges with two equivalent Ir(1)O6 octahedra, and edges with two equivalent Pr(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. The Pr(2)-O(1) bond length is 2.55 Å. There is one shorter (2.31 Å) and one longer (2.33 Å) Pr(2)-O(2) bond length. There are two shorter (2.45 Å) and two longer (2.51 Å) Pr(2)-O(3) bond lengths. Ir(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form IrO6 octahedra that share corners with two equivalent Ir(1)O6 octahedra, corners with four equivalent Pr(2)O7 pentagonal bipyramids, and edges with four equivalent Pr(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. Both Ir(1)-O(1) bond lengths are 2.02 Å. All Ir(1)-O(3) bond lengths are 1.98 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Pr(2) and two equivalent Ir(1) atoms to form distorted OPr2Ir2 trigonal pyramids that share corners with four equivalent O(2)Pr4 tetrahedra and corners with two equivalent O(1)Pr2Ir2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form OPr4 tetrahedra that share corners with six equivalent O(2)Pr4 tetrahedra, corners with two equivalent O(1)Pr2Ir2 trigonal pyramids, and  an edgeedge with one O(2)Pr4 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Pr(2), and one Ir(1) atom.