Nd3Re2O9 crystallizes in the triclinic P-1 space group. There are three inequivalent Nd sites. In the first Nd site, Nd(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 Nd site, Nd(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 Nd site, Nd(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 distorted trigonal non-coplanar geometry to one Nd(1), two equivalent Nd(3), and one Re(2) atom. In the second O site, O(2) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(2) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the third O site, O(3) is bonded to one Nd(1), two equivalent Nd(2), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the fourth O site, O(4) is bonded to one Nd(1), two equivalent Nd(2), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the fifth O site, O(5) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(2) atom to form a mixture of corner and edge-sharing ONd3Re tetrahedra. In the sixth O site, O(6) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(3), and one Re(2) atom. In the eighth O site, O(8) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(3), and two equivalent Re(2) atoms.
Nd3Re2O9 crystallizes in the triclinic P-1 space group. There are three inequivalent Nd sites. In the first Nd site, Nd(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 Nd(1)-O(1) bond length is 2.94 Å. The Nd(1)-O(2) bond length is 2.47 Å. The Nd(1)-O(3) bond length is 2.69 Å. The Nd(1)-O(4) bond length is 2.64 Å. The Nd(1)-O(5) bond length is 2.42 Å. The Nd(1)-O(6) bond length is 2.38 Å. The Nd(1)-O(7) bond length is 2.39 Å. The Nd(1)-O(8) bond length is 2.51 Å. The Nd(1)-O(9) bond length is 2.40 Å. In the second Nd site, Nd(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 Nd(2)-O(2) bond length is 2.61 Å. The Nd(2)-O(5) bond length is 2.38 Å. The Nd(2)-O(6) bond length is 2.71 Å. The Nd(2)-O(8) bond length is 2.41 Å. There is one shorter (2.44 Å) and one longer (2.51 Å) Nd(2)-O(3) bond length. There is one shorter (2.51 Å) and one longer (2.54 Å) Nd(2)-O(4) bond length. In the third Nd site, Nd(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 Nd(3)-O(2) bond length is 2.54 Å. The Nd(3)-O(5) bond length is 2.47 Å. The Nd(3)-O(6) bond length is 2.51 Å. The Nd(3)-O(8) bond length is 2.55 Å. The Nd(3)-O(9) bond length is 2.74 Å. There is one shorter (2.37 Å) and one longer (2.40 Å) Nd(3)-O(1) bond length. There is one shorter (2.48 Å) and one longer (2.81 Å) Nd(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 1.98 Å. The Re(2)-O(2) bond length is 1.94 Å. The Re(2)-O(5) bond length is 1.98 Å. The Re(2)-O(7) bond length is 1.91 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 distorted trigonal non-coplanar geometry to one Nd(1), two equivalent Nd(3), and one Re(2) atom. In the second O site, O(2) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(2) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the third O site, O(3) is bonded to one Nd(1), two equivalent Nd(2), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the fourth O site, O(4) is bonded to one Nd(1), two equivalent Nd(2), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the fifth O site, O(5) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(2) atom to form a mixture of corner and edge-sharing ONd3Re tetrahedra. In the sixth O site, O(6) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(3), and one Re(2) atom. In the eighth O site, O(8) is bonded to one Nd(1), one Nd(2), one Nd(3), and one Re(1) atom to form a mixture of distorted corner and edge-sharing ONd3Re tetrahedra. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(3), and two equivalent Re(2) atoms.