Pr3Re2O9 crystallizes in the triclinic P-1 space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the second Pr site, Pr(2) is bonded in a distorted body-centered cubic geometry to one O(2), one O(5), one O(6), one O(8), two equivalent O(3), and two equivalent O(4) atoms. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to one O(2), one O(5), one O(6), one O(8), one O(9), two equivalent O(1), and two equivalent O(7) atoms. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded in a distorted square co-planar geometry to one O(3), one O(4), one O(6), and one O(8) atom. In the second Re site, Re(2) is bonded to one O(1), one O(2), one O(5), one O(7), and two equivalent O(9) atoms to form edge-sharing ReO6 octahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Pr(1), two equivalent Pr(3), and one Re(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(3), and one Re(2) atom. In the third O site, O(3) is bonded to one Pr(1), two equivalent Pr(2), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the fourth O site, O(4) is bonded to one Pr(1), two equivalent Pr(2), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the fifth O site, O(5) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(2) atom to form a mixture of edge and corner-sharing OPr3Re tetrahedra. In the sixth O site, O(6) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Pr(3), and one Re(2) atom. In the eighth O site, O(8) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Pr(1), one Pr(3), and two equivalent Re(2) atoms.
Pr3Re2O9 crystallizes in the triclinic P-1 space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The Pr(1)-O(1) bond length is 2.93 Å. The Pr(1)-O(2) bond length is 2.50 Å. The Pr(1)-O(3) bond length is 2.71 Å. The Pr(1)-O(4) bond length is 2.65 Å. The Pr(1)-O(5) bond length is 2.43 Å. The Pr(1)-O(6) bond length is 2.40 Å. The Pr(1)-O(7) bond length is 2.41 Å. The Pr(1)-O(8) bond length is 2.52 Å. The Pr(1)-O(9) bond length is 2.42 Å. In the second Pr site, Pr(2) is bonded in a distorted body-centered cubic geometry to one O(2), one O(5), one O(6), one O(8), two equivalent O(3), and two equivalent O(4) atoms. The Pr(2)-O(2) bond length is 2.62 Å. The Pr(2)-O(5) bond length is 2.43 Å. The Pr(2)-O(6) bond length is 2.68 Å. The Pr(2)-O(8) bond length is 2.44 Å. There is one shorter (2.48 Å) and one longer (2.51 Å) Pr(2)-O(3) bond length. There is one shorter (2.52 Å) and one longer (2.59 Å) Pr(2)-O(4) bond length. In the third Pr site, Pr(3) is bonded in a 9-coordinate geometry to one O(2), one O(5), one O(6), one O(8), one O(9), two equivalent O(1), and two equivalent O(7) atoms. The Pr(3)-O(2) bond length is 2.62 Å. The Pr(3)-O(5) bond length is 2.48 Å. The Pr(3)-O(6) bond length is 2.55 Å. The Pr(3)-O(8) bond length is 2.57 Å. The Pr(3)-O(9) bond length is 2.78 Å. There is one shorter (2.40 Å) and one longer (2.41 Å) Pr(3)-O(1) bond length. There is one shorter (2.52 Å) and one longer (2.72 Å) Pr(3)-O(7) bond length. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded in a distorted square co-planar geometry to one O(3), one O(4), one O(6), and one O(8) atom. The Re(1)-O(3) bond length is 1.94 Å. The Re(1)-O(4) bond length is 1.93 Å. The Re(1)-O(6) bond length is 1.92 Å. The Re(1)-O(8) bond length is 1.93 Å. In the second Re site, Re(2) is bonded to one O(1), one O(2), one O(5), one O(7), and two equivalent O(9) atoms to form edge-sharing ReO6 octahedra. The Re(2)-O(1) bond length is 1.99 Å. The Re(2)-O(2) bond length is 1.93 Å. The Re(2)-O(5) bond length is 1.97 Å. The Re(2)-O(7) bond length is 1.92 Å. There is one shorter (2.03 Å) and one longer (2.04 Å) Re(2)-O(9) bond length. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Pr(1), two equivalent Pr(3), and one Re(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Pr(1), one Pr(2), one Pr(3), and one Re(2) atom. In the third O site, O(3) is bonded to one Pr(1), two equivalent Pr(2), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the fourth O site, O(4) is bonded to one Pr(1), two equivalent Pr(2), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the fifth O site, O(5) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(2) atom to form a mixture of edge and corner-sharing OPr3Re tetrahedra. In the sixth O site, O(6) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Pr(3), and one Re(2) atom. In the eighth O site, O(8) is bonded to one Pr(1), one Pr(2), one Pr(3), and one Re(1) atom to form a mixture of distorted edge and corner-sharing OPr3Re tetrahedra. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Pr(1), one Pr(3), and two equivalent Re(2) atoms.