Bi16O25 crystallizes in the tetragonal I-42m space group. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms. In the second Bi site, Bi(2) is bonded to one O(4), one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing BiO7 pentagonal bipyramids. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and two equivalent Bi(3) atoms. In the second O site, O(2) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fourth O site, O(4) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded to four equivalent Bi(2) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra.
Bi16O25 crystallizes in the tetragonal I-42m space group. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms. The Bi(1)-O(4) bond length is 2.12 Å. The Bi(1)-O(5) bond length is 2.66 Å. Both Bi(1)-O(1) bond lengths are 2.73 Å. Both Bi(1)-O(3) bond lengths are 2.22 Å. In the second Bi site, Bi(2) is bonded to one O(4), one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing BiO7 pentagonal bipyramids. The Bi(2)-O(4) bond length is 2.25 Å. The Bi(2)-O(5) bond length is 2.61 Å. The Bi(2)-O(6) bond length is 2.42 Å. Both Bi(2)-O(2) bond lengths are 2.64 Å. Both Bi(2)-O(3) bond lengths are 2.23 Å. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. The Bi(3)-O(1) bond length is 2.23 Å. The Bi(3)-O(2) bond length is 2.26 Å. The Bi(3)-O(4) bond length is 2.58 Å. The Bi(3)-O(5) bond length is 2.14 Å. There is one shorter (2.68 Å) and one longer (2.71 Å) Bi(3)-O(3) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and two equivalent Bi(3) atoms. In the second O site, O(2) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fourth O site, O(4) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded to one Bi(1), one Bi(2), and two equivalent Bi(3) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the sixth O site, O(6) is bonded to four equivalent Bi(2) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra.