CuNd2Ge2O8 crystallizes in the monoclinic Cm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), 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 8-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. Cu(1) is bonded in a 4-coordinate geometry to one O(1), one O(5), one O(7), and one O(8) atom. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(4), one O(9), and two equivalent O(7) atoms. In the second Ge site, Ge(2) is bonded to one O(1), one O(10), one O(5), one O(6), and one O(8) atom to form corner-sharing GeO5 trigonal bipyramids. In the third Ge site, Ge(3) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing GeO4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Nd(2) and one Ge(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nd(1) and one Ge(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nd(2) and one Ge(1) atom. In the fifth O site, O(5) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Nd(1), one Nd(2), one Ge(2), and one Ge(3) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(2), one Cu(1), and one Ge(1) atom. In the eighth O site, O(8) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to two equivalent Nd(1) and one Ge(1) atom. In the tenth O site, O(10) is bonded in a 1-coordinate geometry to one Nd(1), one Nd(2), and one Ge(2) atom.
CuNd2Ge2O8 crystallizes in the monoclinic Cm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), 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 2.51 Å. The Nd(1)-O(10) bond length is 2.45 Å. The Nd(1)-O(3) bond length is 2.40 Å. The Nd(1)-O(5) bond length is 2.43 Å. The Nd(1)-O(6) bond length is 2.83 Å. The Nd(1)-O(7) bond length is 2.66 Å. The Nd(1)-O(8) bond length is 2.51 Å. The Nd(1)-O(9) bond length is 2.36 Å. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Nd(2)-O(1) bond length is 2.50 Å. The Nd(2)-O(10) bond length is 2.53 Å. The Nd(2)-O(2) bond length is 2.37 Å. The Nd(2)-O(4) bond length is 2.37 Å. The Nd(2)-O(5) bond length is 2.35 Å. The Nd(2)-O(6) bond length is 2.77 Å. The Nd(2)-O(7) bond length is 2.93 Å. The Nd(2)-O(8) bond length is 2.46 Å. Cu(1) is bonded in a 4-coordinate geometry to one O(1), one O(5), one O(7), and one O(8) atom. The Cu(1)-O(1) bond length is 2.01 Å. The Cu(1)-O(5) bond length is 1.90 Å. The Cu(1)-O(7) bond length is 1.99 Å. The Cu(1)-O(8) bond length is 2.09 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a tetrahedral geometry to one O(4), one O(9), and two equivalent O(7) atoms. The Ge(1)-O(4) bond length is 1.79 Å. The Ge(1)-O(9) bond length is 1.79 Å. Both Ge(1)-O(7) bond lengths are 1.80 Å. In the second Ge site, Ge(2) is bonded to one O(1), one O(10), one O(5), one O(6), and one O(8) atom to form corner-sharing GeO5 trigonal bipyramids. The Ge(2)-O(1) bond length is 1.81 Å. The Ge(2)-O(10) bond length is 1.78 Å. The Ge(2)-O(5) bond length is 1.97 Å. The Ge(2)-O(6) bond length is 1.99 Å. The Ge(2)-O(8) bond length is 1.82 Å. In the third Ge site, Ge(3) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing GeO4 tetrahedra. The Ge(3)-O(2) bond length is 1.77 Å. The Ge(3)-O(3) bond length is 1.77 Å. Both Ge(3)-O(6) bond lengths are 1.81 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Nd(2) and one Ge(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nd(1) and one Ge(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nd(2) and one Ge(1) atom. In the fifth O site, O(5) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Nd(1), one Nd(2), one Ge(2), and one Ge(3) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(2), one Cu(1), and one Ge(1) atom. In the eighth O site, O(8) is bonded to one Nd(1), one Nd(2), one Cu(1), and one Ge(2) atom to form a mixture of distorted corner and edge-sharing ONd2CuGe trigonal pyramids. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to two equivalent Nd(1) and one Ge(1) atom. In the tenth O site, O(10) is bonded in a 1-coordinate geometry to one Nd(1), one Nd(2), and one Ge(2) atom.