Pr3MoO7 crystallizes in the orthorhombic P2_12_12_1 space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(7) atoms. In the second Pr site, Pr(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. In the third Pr site, Pr(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form distorted PrO7 pentagonal bipyramids that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Pr(3)O7 pentagonal bipyramids, and edges with two equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-40°. Mo(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms to form MoO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Pr(3)O7 pentagonal bipyramids, and edges with two equivalent Pr(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 29°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), and one Mo(1) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), and one Mo(1) atom. In the third O site, O(7) is bonded to two equivalent Pr(1) and two equivalent Pr(3) atoms to form OPr4 tetrahedra that share corners with two equivalent O(2)Pr3Mo tetrahedra, corners with two equivalent O(4)Pr3Mo tetrahedra, corners with two equivalent O(1)Pr4 tetrahedra, corners with four equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(2)Pr3Mo tetrahedra,  an edgeedge with one O(4)Pr3Mo tetrahedra, and  an edgeedge with one O(1)Pr4 tetrahedra. In the fourth O site, O(1) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form OPr4 tetrahedra that share corners with two equivalent O(2)Pr3Mo tetrahedra, corners with two equivalent O(4)Pr3Mo tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra, corners with four equivalent O(1)Pr4 tetrahedra,  an edgeedge with one O(2)Pr3Mo tetrahedra,  an edgeedge with one O(4)Pr3Mo tetrahedra, and  an edgeedge with one O(7)Pr4 tetrahedra. In the fifth O site, O(2) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Mo(1) atom to form distorted OPr3Mo tetrahedra that share corners with two equivalent O(1)Pr4 tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(1)Pr4 tetrahedra,  an edgeedge with one O(7)Pr4 tetrahedra, and edges with two equivalent O(4)Pr3Mo tetrahedra. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(2), one Pr(3), and two equivalent Mo(1) atoms. In the seventh O site, O(4) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Mo(1) atom to form distorted OPr3Mo tetrahedra that share corners with two equivalent O(1)Pr4 tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(1)Pr4 tetrahedra,  an edgeedge with one O(7)Pr4 tetrahedra, and edges with two equivalent O(2)Pr3Mo tetrahedra.
Pr3MoO7 crystallizes in the orthorhombic P2_12_12_1 space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(7) atoms. The Pr(1)-O(2) bond length is 2.48 Å. The Pr(1)-O(4) bond length is 2.41 Å. There is one shorter (2.41 Å) and one longer (2.43 Å) Pr(1)-O(1) bond length. There is one shorter (2.42 Å) and one longer (2.44 Å) Pr(1)-O(7) bond length. In the second Pr site, Pr(2) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms. The Pr(2)-O(2) bond length is 2.51 Å. The Pr(2)-O(3) bond length is 2.69 Å. The Pr(2)-O(4) bond length is 2.42 Å. The Pr(2)-O(5) bond length is 2.46 Å. The Pr(2)-O(6) bond length is 2.50 Å. There is one shorter (2.33 Å) and one longer (2.37 Å) Pr(2)-O(1) bond length. In the third Pr site, Pr(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form distorted PrO7 pentagonal bipyramids that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Pr(3)O7 pentagonal bipyramids, and edges with two equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-40°. The Pr(3)-O(2) bond length is 2.46 Å. The Pr(3)-O(3) bond length is 2.64 Å. The Pr(3)-O(4) bond length is 2.47 Å. The Pr(3)-O(5) bond length is 2.51 Å. The Pr(3)-O(6) bond length is 2.47 Å. Both Pr(3)-O(7) bond lengths are 2.33 Å. Mo(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms to form MoO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Pr(3)O7 pentagonal bipyramids, and edges with two equivalent Pr(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 29°. The Mo(1)-O(2) bond length is 2.02 Å. The Mo(1)-O(4) bond length is 2.08 Å. The Mo(1)-O(5) bond length is 1.92 Å. The Mo(1)-O(6) bond length is 1.89 Å. There is one shorter (1.96 Å) and one longer (1.97 Å) Mo(1)-O(3) bond length. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), and one Mo(1) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Pr(2), one Pr(3), and one Mo(1) atom. In the third O site, O(7) is bonded to two equivalent Pr(1) and two equivalent Pr(3) atoms to form OPr4 tetrahedra that share corners with two equivalent O(2)Pr3Mo tetrahedra, corners with two equivalent O(4)Pr3Mo tetrahedra, corners with two equivalent O(1)Pr4 tetrahedra, corners with four equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(2)Pr3Mo tetrahedra,  an edgeedge with one O(4)Pr3Mo tetrahedra, and  an edgeedge with one O(1)Pr4 tetrahedra. In the fourth O site, O(1) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form OPr4 tetrahedra that share corners with two equivalent O(2)Pr3Mo tetrahedra, corners with two equivalent O(4)Pr3Mo tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra, corners with four equivalent O(1)Pr4 tetrahedra,  an edgeedge with one O(2)Pr3Mo tetrahedra,  an edgeedge with one O(4)Pr3Mo tetrahedra, and  an edgeedge with one O(7)Pr4 tetrahedra. In the fifth O site, O(2) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Mo(1) atom to form distorted OPr3Mo tetrahedra that share corners with two equivalent O(1)Pr4 tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(1)Pr4 tetrahedra,  an edgeedge with one O(7)Pr4 tetrahedra, and edges with two equivalent O(4)Pr3Mo tetrahedra. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(2), one Pr(3), and two equivalent Mo(1) atoms. In the seventh O site, O(4) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Mo(1) atom to form distorted OPr3Mo tetrahedra that share corners with two equivalent O(1)Pr4 tetrahedra, corners with two equivalent O(7)Pr4 tetrahedra,  an edgeedge with one O(1)Pr4 tetrahedra,  an edgeedge with one O(7)Pr4 tetrahedra, and edges with two equivalent O(2)Pr3Mo tetrahedra.