Nd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Nd site, Nd(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent Nd(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Nd(2)O7 pentagonal bipyramids, and edges with four equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 30°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Nd(2) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Ta(1) atom. In the third O site, O(3) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra.
Nd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. All Nd(1)-O(2) bond lengths are 2.74 Å. All Nd(1)-O(3) bond lengths are 2.40 Å. In the second Nd site, Nd(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent Nd(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. The Nd(2)-O(1) bond length is 2.68 Å. There is one shorter (2.30 Å) and one longer (2.31 Å) Nd(2)-O(3) bond length. All Nd(2)-O(2) bond lengths are 2.45 Å. Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Nd(2)O7 pentagonal bipyramids, and edges with four equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 30°. Both Ta(1)-O(1) bond lengths are 1.99 Å. All Ta(1)-O(2) bond lengths are 1.99 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Nd(2) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Ta(1) atom. In the third O site, O(3) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra.