BaNb4O11 crystallizes in the hexagonal P6_322 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(3) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in an octahedral geometry to six equivalent O(3) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1) and three equivalent Nb(2) atoms to form distorted corner-sharing OBaNb3 tetrahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Nb(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Nb(1), and one Nb(2) atom.
BaNb4O11 crystallizes in the hexagonal P6_322 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(3) atoms. Both Ba(1)-O(1) bond lengths are 2.74 Å. All Ba(1)-O(3) bond lengths are 2.64 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in an octahedral geometry to six equivalent O(3) atoms. All Nb(1)-O(3) bond lengths are 2.02 Å. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Nb(2)-O(1) bond lengths are 2.11 Å. Both Nb(2)-O(2) bond lengths are 2.01 Å. Both Nb(2)-O(3) bond lengths are 1.99 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1) and three equivalent Nb(2) atoms to form distorted corner-sharing OBaNb3 tetrahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Nb(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Nb(1), and one Nb(2) atom.