Ba8V7O22 crystallizes in the trigonal R-3m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), three equivalent O(5), and six equivalent O(3) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(4) atoms. In the third Ba site, Ba(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted BaO6 cuboctahedra that share corners with three equivalent V(2)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra, and  a faceface with one V(4)O6 octahedra. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to nine equivalent O(5) atoms. There are four inequivalent V sites. In the first V site, V(1) is bonded to six equivalent O(5) atoms to form face-sharing VO6 octahedra. In the second V site, V(2) is bonded to one O(2) and three equivalent O(3) atoms to form VO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra and corners with three equivalent V(4)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. In the third V site, V(3) is bonded to one O(1) and three equivalent O(4) atoms to form VO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra. In the fourth V site, V(4) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form VO6 octahedra that share corners with three equivalent V(2)O4 tetrahedra,  a faceface with one Ba(3)O6 cuboctahedra, and  a faceface with one V(1)O6 octahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one V(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(2) and one V(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(3), two equivalent Ba(1), one V(2), and one V(4) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(3), three equivalent Ba(2), and one V(3) atom. In the fifth O site, O(5) is bonded to one Ba(1), three equivalent Ba(4), one V(1), and one V(4) atom to form a mixture of distorted edge, face, and corner-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°.
Ba8V7O22 crystallizes in the trigonal R-3m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), three equivalent O(5), and six equivalent O(3) atoms. The Ba(1)-O(1) bond length is 2.82 Å. All Ba(1)-O(5) bond lengths are 2.66 Å. All Ba(1)-O(3) bond lengths are 3.03 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(4) atoms. The Ba(2)-O(2) bond length is 2.65 Å. There are three shorter (2.86 Å) and six longer (3.00 Å) Ba(2)-O(4) bond lengths. In the third Ba site, Ba(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted BaO6 cuboctahedra that share corners with three equivalent V(2)O4 tetrahedra, corners with three equivalent V(3)O4 tetrahedra, and  a faceface with one V(4)O6 octahedra. All Ba(3)-O(3) bond lengths are 2.88 Å. All Ba(3)-O(4) bond lengths are 2.76 Å. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to nine equivalent O(5) atoms. There are three shorter (2.79 Å) and six longer (2.98 Å) Ba(4)-O(5) bond lengths. There are four inequivalent V sites. In the first V site, V(1) is bonded to six equivalent O(5) atoms to form face-sharing VO6 octahedra. All V(1)-O(5) bond lengths are 2.00 Å. In the second V site, V(2) is bonded to one O(2) and three equivalent O(3) atoms to form VO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra and corners with three equivalent V(4)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. The V(2)-O(2) bond length is 1.73 Å. All V(2)-O(3) bond lengths are 1.78 Å. In the third V site, V(3) is bonded to one O(1) and three equivalent O(4) atoms to form VO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra. The V(3)-O(1) bond length is 1.72 Å. All V(3)-O(4) bond lengths are 1.76 Å. In the fourth V site, V(4) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form VO6 octahedra that share corners with three equivalent V(2)O4 tetrahedra,  a faceface with one Ba(3)O6 cuboctahedra, and  a faceface with one V(1)O6 octahedra. All V(4)-O(3) bond lengths are 2.15 Å. All V(4)-O(5) bond lengths are 2.07 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one V(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(2) and one V(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(3), two equivalent Ba(1), one V(2), and one V(4) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(3), three equivalent Ba(2), and one V(3) atom. In the fifth O site, O(5) is bonded to one Ba(1), three equivalent Ba(4), one V(1), and one V(4) atom to form a mixture of distorted edge, face, and corner-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°.