Ta2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(5), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-35°. In the second Ta site, Ta(2) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(2), two equivalent O(4), and two equivalent O(8) atoms. In the third Ta site, Ta(3) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 13-32°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ta(3) and two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ta(3) and two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Ta(3) atoms. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ta(2) and two equivalent Ta(3) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent Ta(2) atoms.
Ta2O5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(5), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-35°. The Ta(1)-O(5) bond length is 2.23 Å. The Ta(1)-O(7) bond length is 1.92 Å. Both Ta(1)-O(1) bond lengths are 1.99 Å. There is one shorter (1.97 Å) and one longer (2.05 Å) Ta(1)-O(3) bond length. In the second Ta site, Ta(2) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(2), two equivalent O(4), and two equivalent O(8) atoms. The Ta(2)-O(6) bond length is 2.56 Å. There is one shorter (1.94 Å) and one longer (1.96 Å) Ta(2)-O(2) bond length. Both Ta(2)-O(4) bond lengths are 2.16 Å. Both Ta(2)-O(8) bond lengths are 1.91 Å. In the third Ta site, Ta(3) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 13-32°. The Ta(3)-O(3) bond length is 2.17 Å. The Ta(3)-O(4) bond length is 1.93 Å. Both Ta(3)-O(5) bond lengths are 1.99 Å. Both Ta(3)-O(6) bond lengths are 2.00 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ta(3) and two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ta(3) and two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Ta(3) atoms. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ta(2) and two equivalent Ta(3) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent Ta(2) atoms.