BaV4AlO7 crystallizes in the hexagonal P6_3mc space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(3) and six equivalent O(1) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. In the second V site, V(2) is bonded to one O(2) and three equivalent O(1) atoms to form VO4 trigonal pyramids that share corners with three equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. Al(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form AlO6 octahedra that share corners with three equivalent V(2)O4 trigonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one V(1), one V(2), and one Al(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one V(2) and three equivalent V(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), two equivalent V(1), and one Al(1) atom.
BaV4AlO7 crystallizes in the hexagonal P6_3mc space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(3) and six equivalent O(1) atoms. All Ba(1)-O(3) bond lengths are 2.74 Å. All Ba(1)-O(1) bond lengths are 3.01 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. The V(1)-O(1) bond length is 1.99 Å. The V(1)-O(2) bond length is 2.05 Å. Both V(1)-O(3) bond lengths are 2.06 Å. In the second V site, V(2) is bonded to one O(2) and three equivalent O(1) atoms to form VO4 trigonal pyramids that share corners with three equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. The V(2)-O(2) bond length is 1.95 Å. All V(2)-O(1) bond lengths are 1.93 Å. Al(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form AlO6 octahedra that share corners with three equivalent V(2)O4 trigonal pyramids. All Al(1)-O(1) bond lengths are 2.04 Å. All Al(1)-O(3) bond lengths are 1.93 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one V(1), one V(2), and one Al(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one V(2) and three equivalent V(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), two equivalent V(1), and one Al(1) atom.