BaBi4O7 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(6), and two equivalent O(7) atoms. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(1) atoms. In the third Bi site, Bi(3) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(5), and two equivalent O(3) atoms. In the fourth Bi site, Bi(4) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(5) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Bi(1), and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to two equivalent Ba(1), one Bi(2), and one Bi(3) atom to form distorted OBa2Bi2 tetrahedra that share corners with two equivalent O(2)Ba2Bi2 tetrahedra and edges with two equivalent O(3)BaBi3 trigonal pyramids. In the third O site, O(3) is bonded to one Ba(1), one Bi(4), and two equivalent Bi(3) atoms to form distorted OBaBi3 trigonal pyramids that share corners with two equivalent O(3)BaBi3 trigonal pyramids and edges with two equivalent O(2)Ba2Bi2 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Bi(2), and one Bi(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Bi(3) and two equivalent Bi(4) atoms. In the sixth O site, O(6) is bonded in a water-like geometry to one Ba(1) and one Bi(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms.
BaBi4O7 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms. The Ba(1)-O(1) bond length is 3.26 Å. The Ba(1)-O(3) bond length is 3.16 Å. The Ba(1)-O(6) bond length is 2.53 Å. Both Ba(1)-O(2) bond lengths are 2.83 Å. Both Ba(1)-O(4) bond lengths are 2.78 Å. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(6), and two equivalent O(7) atoms. The Bi(1)-O(1) bond length is 2.27 Å. The Bi(1)-O(6) bond length is 2.02 Å. Both Bi(1)-O(7) bond lengths are 2.32 Å. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(1) atoms. The Bi(2)-O(2) bond length is 2.18 Å. The Bi(2)-O(4) bond length is 2.81 Å. The Bi(2)-O(7) bond length is 2.14 Å. Both Bi(2)-O(1) bond lengths are 2.31 Å. In the third Bi site, Bi(3) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(5), and two equivalent O(3) atoms. The Bi(3)-O(2) bond length is 2.11 Å. The Bi(3)-O(5) bond length is 2.14 Å. Both Bi(3)-O(3) bond lengths are 2.33 Å. In the fourth Bi site, Bi(4) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(5) atoms. The Bi(4)-O(3) bond length is 2.20 Å. The Bi(4)-O(4) bond length is 2.05 Å. Both Bi(4)-O(5) bond lengths are 2.34 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Bi(1), and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to two equivalent Ba(1), one Bi(2), and one Bi(3) atom to form distorted OBa2Bi2 tetrahedra that share corners with two equivalent O(2)Ba2Bi2 tetrahedra and edges with two equivalent O(3)BaBi3 trigonal pyramids. In the third O site, O(3) is bonded to one Ba(1), one Bi(4), and two equivalent Bi(3) atoms to form distorted OBaBi3 trigonal pyramids that share corners with two equivalent O(3)BaBi3 trigonal pyramids and edges with two equivalent O(2)Ba2Bi2 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Bi(2), and one Bi(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Bi(3) and two equivalent Bi(4) atoms. In the sixth O site, O(6) is bonded in a water-like geometry to one Ba(1) and one Bi(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms.