Sc3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. In the second Sc site, Sc(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 68°. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sc(1) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded to one Sc(2), two equivalent Sc(1), and one Ta(1) atom to form distorted OSc3Ta tetrahedra that share corners with two equivalent O(3)Sc4 tetrahedra, corners with eight equivalent O(2)Sc3Ta tetrahedra,  an edgeedge with one O(3)Sc4 tetrahedra, and edges with two equivalent O(2)Sc3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Sc(1) and two equivalent Sc(2) atoms to form OSc4 tetrahedra that share corners with two equivalent O(3)Sc4 tetrahedra, corners with eight equivalent O(2)Sc3Ta tetrahedra, and edges with four equivalent O(2)Sc3Ta tetrahedra.
Sc3TaO7 crystallizes in the orthorhombic Cmme space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. The Sc(1)-O(3) bond length is 2.09 Å. There is one shorter (1.93 Å) and one longer (2.56 Å) Sc(1)-O(1) bond length. There are two shorter (2.06 Å) and two longer (2.43 Å) Sc(1)-O(2) bond lengths. In the second Sc site, Sc(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form distorted corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 68°. Both Sc(2)-O(3) bond lengths are 2.16 Å. All Sc(2)-O(2) bond lengths are 2.12 Å. Ta(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Ta(1)-O(1) bond lengths are 2.13 Å. All Ta(1)-O(2) bond lengths are 2.17 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sc(1) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded to one Sc(2), two equivalent Sc(1), and one Ta(1) atom to form distorted OSc3Ta tetrahedra that share corners with two equivalent O(3)Sc4 tetrahedra, corners with eight equivalent O(2)Sc3Ta tetrahedra,  an edgeedge with one O(3)Sc4 tetrahedra, and edges with two equivalent O(2)Sc3Ta tetrahedra. In the third O site, O(3) is bonded to two equivalent Sc(1) and two equivalent Sc(2) atoms to form OSc4 tetrahedra that share corners with two equivalent O(3)Sc4 tetrahedra, corners with eight equivalent O(2)Sc3Ta tetrahedra, and edges with four equivalent O(2)Sc3Ta tetrahedra.