TaCuO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(4) atoms. In the second Ta site, Ta(2) is bonded in a tetrahedral geometry to one O(3), one O(5), one O(6), and one O(8) atom. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(5), and one O(7) atom. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(8), and two equivalent O(2) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ta(1) and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Cu(2) atoms. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ta(2) and one Cu(1) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to two equivalent Ta(1) and one Cu(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ta(2) and one Cu(1) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Ta(1), one Ta(2), and one Cu(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ta(1) and one Cu(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ta(2) and one Cu(2) atom.
TaCuO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(4) atoms. The Ta(1)-O(1) bond length is 1.89 Å. The Ta(1)-O(2) bond length is 1.90 Å. The Ta(1)-O(6) bond length is 2.55 Å. The Ta(1)-O(7) bond length is 1.85 Å. There is one shorter (1.98 Å) and one longer (2.26 Å) Ta(1)-O(4) bond length. In the second Ta site, Ta(2) is bonded in a tetrahedral geometry to one O(3), one O(5), one O(6), and one O(8) atom. The Ta(2)-O(3) bond length is 1.86 Å. The Ta(2)-O(5) bond length is 1.88 Å. The Ta(2)-O(6) bond length is 1.94 Å. The Ta(2)-O(8) bond length is 1.81 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(5), and one O(7) atom. The Cu(1)-O(1) bond length is 1.86 Å. The Cu(1)-O(3) bond length is 1.83 Å. The Cu(1)-O(5) bond length is 1.86 Å. The Cu(1)-O(7) bond length is 1.83 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(8), and two equivalent O(2) atoms. The Cu(2)-O(4) bond length is 1.85 Å. The Cu(2)-O(6) bond length is 1.91 Å. The Cu(2)-O(8) bond length is 1.88 Å. There is one shorter (1.83 Å) and one longer (2.33 Å) Cu(2)-O(2) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ta(1) and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Cu(2) atoms. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Ta(2) and one Cu(1) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to two equivalent Ta(1) and one Cu(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ta(2) and one Cu(1) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Ta(1), one Ta(2), and one Cu(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ta(1) and one Cu(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ta(2) and one Cu(2) atom.