Ba2V2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a body-centered cubic geometry to one O(10), one O(7), one O(8), one O(9), two equivalent O(3), and two equivalent O(6) atoms. In the second Ba site, Ba(2) is bonded in a body-centered cubic geometry to one O(10), one O(7), one O(8), one O(9), two equivalent O(4), and two equivalent O(5) atoms. In the third Ba site, Ba(3) is bonded to one O(10), one O(7), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(4)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent V(1)O5 square pyramids, faces with two equivalent V(2)O5 square pyramids, faces with two equivalent V(3)O5 square pyramids, and faces with two equivalent V(4)O5 square pyramids. In the fourth Ba site, Ba(4) is bonded to one O(10), one O(7), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent V(1)O5 square pyramids, faces with two equivalent V(2)O5 square pyramids, faces with two equivalent V(3)O5 square pyramids, and faces with two equivalent V(4)O5 square pyramids. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(8) atoms to form VO5 square pyramids that share  a cornercorner with one V(2)O5 square pyramid, corners with two equivalent V(1)O5 square pyramids, corners with two equivalent V(3)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. In the second V site, V(2) is bonded to one O(2), one O(5), one O(6), and two equivalent O(10) atoms to form VO5 square pyramids that share  a cornercorner with one V(1)O5 square pyramid, corners with two equivalent V(2)O5 square pyramids, corners with two equivalent V(4)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. In the third V site, V(3) is bonded to one O(1), one O(3), one O(4), and two equivalent O(7) atoms to form VO5 square pyramids that share  a cornercorner with one V(4)O5 square pyramid, corners with two equivalent V(1)O5 square pyramids, corners with two equivalent V(3)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. In the fourth V site, V(4) is bonded to one O(1), one O(5), one O(6), and two equivalent O(9) atoms to form VO5 square pyramids that share  a cornercorner with one V(3)O5 square pyramid, corners with two equivalent V(2)O5 square pyramids, corners with two equivalent V(4)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(3), two equivalent Ba(4), one V(3), and one V(4) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(3), two equivalent Ba(4), one V(1), and one V(2) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(3), one V(1), and one V(3) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 61-62°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Ba(4), one V(1), and one V(3) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), one V(2), and one V(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(4), one V(2), and one V(4) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(3) atoms. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(1) atoms. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(4) atoms. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(2) atoms.
Ba2V2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a body-centered cubic geometry to one O(10), one O(7), one O(8), one O(9), two equivalent O(3), and two equivalent O(6) atoms. The Ba(1)-O(10) bond length is 2.78 Å. The Ba(1)-O(7) bond length is 2.78 Å. The Ba(1)-O(8) bond length is 2.77 Å. The Ba(1)-O(9) bond length is 2.76 Å. There is one shorter (2.78 Å) and one longer (2.80 Å) Ba(1)-O(3) bond length. There is one shorter (2.76 Å) and one longer (2.78 Å) Ba(1)-O(6) bond length. In the second Ba site, Ba(2) is bonded in a body-centered cubic geometry to one O(10), one O(7), one O(8), one O(9), two equivalent O(4), and two equivalent O(5) atoms. The Ba(2)-O(10) bond length is 2.77 Å. The Ba(2)-O(7) bond length is 2.78 Å. The Ba(2)-O(8) bond length is 2.78 Å. The Ba(2)-O(9) bond length is 2.77 Å. There is one shorter (2.78 Å) and one longer (2.79 Å) Ba(2)-O(4) bond length. Both Ba(2)-O(5) bond lengths are 2.78 Å. In the third Ba site, Ba(3) is bonded to one O(10), one O(7), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(4)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent V(1)O5 square pyramids, faces with two equivalent V(2)O5 square pyramids, faces with two equivalent V(3)O5 square pyramids, and faces with two equivalent V(4)O5 square pyramids. The Ba(3)-O(10) bond length is 3.03 Å. The Ba(3)-O(7) bond length is 3.03 Å. The Ba(3)-O(8) bond length is 3.02 Å. The Ba(3)-O(9) bond length is 3.06 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Ba(3)-O(1) bond length. There is one shorter (2.83 Å) and one longer (2.87 Å) Ba(3)-O(2) bond length. Both Ba(3)-O(3) bond lengths are 3.00 Å. There is one shorter (3.01 Å) and one longer (3.02 Å) Ba(3)-O(5) bond length. In the fourth Ba site, Ba(4) is bonded to one O(10), one O(7), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with two equivalent V(1)O5 square pyramids, faces with two equivalent V(2)O5 square pyramids, faces with two equivalent V(3)O5 square pyramids, and faces with two equivalent V(4)O5 square pyramids. The Ba(4)-O(10) bond length is 3.03 Å. The Ba(4)-O(7) bond length is 3.04 Å. The Ba(4)-O(8) bond length is 3.03 Å. The Ba(4)-O(9) bond length is 3.02 Å. There is one shorter (2.84 Å) and one longer (2.86 Å) Ba(4)-O(1) bond length. There is one shorter (2.84 Å) and one longer (2.88 Å) Ba(4)-O(2) bond length. There is one shorter (3.00 Å) and one longer (3.02 Å) Ba(4)-O(4) bond length. Both Ba(4)-O(6) bond lengths are 3.01 Å. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(8) atoms to form VO5 square pyramids that share  a cornercorner with one V(2)O5 square pyramid, corners with two equivalent V(1)O5 square pyramids, corners with two equivalent V(3)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The V(1)-O(2) bond length is 1.99 Å. The V(1)-O(3) bond length is 2.04 Å. The V(1)-O(4) bond length is 2.04 Å. There is one shorter (1.95 Å) and one longer (2.11 Å) V(1)-O(8) bond length. In the second V site, V(2) is bonded to one O(2), one O(5), one O(6), and two equivalent O(10) atoms to form VO5 square pyramids that share  a cornercorner with one V(1)O5 square pyramid, corners with two equivalent V(2)O5 square pyramids, corners with two equivalent V(4)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The V(2)-O(2) bond length is 1.99 Å. The V(2)-O(5) bond length is 2.05 Å. The V(2)-O(6) bond length is 2.02 Å. There is one shorter (1.95 Å) and one longer (2.11 Å) V(2)-O(10) bond length. In the third V site, V(3) is bonded to one O(1), one O(3), one O(4), and two equivalent O(7) atoms to form VO5 square pyramids that share  a cornercorner with one V(4)O5 square pyramid, corners with two equivalent V(1)O5 square pyramids, corners with two equivalent V(3)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The V(3)-O(1) bond length is 2.00 Å. The V(3)-O(3) bond length is 2.04 Å. The V(3)-O(4) bond length is 2.04 Å. There is one shorter (1.96 Å) and one longer (2.11 Å) V(3)-O(7) bond length. In the fourth V site, V(4) is bonded to one O(1), one O(5), one O(6), and two equivalent O(9) atoms to form VO5 square pyramids that share  a cornercorner with one V(3)O5 square pyramid, corners with two equivalent V(2)O5 square pyramids, corners with two equivalent V(4)O5 square pyramids, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(4)O12 cuboctahedra. The V(4)-O(1) bond length is 1.97 Å. The V(4)-O(5) bond length is 2.03 Å. The V(4)-O(6) bond length is 2.06 Å. There is one shorter (1.97 Å) and one longer (2.10 Å) V(4)-O(9) bond length. There are ten inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(3), two equivalent Ba(4), one V(3), and one V(4) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(3), two equivalent Ba(4), one V(1), and one V(2) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(3), one V(1), and one V(3) atom to form a mixture of distorted corner, face, and edge-sharing OBa4V2 octahedra. The corner-sharing octahedral tilt angles range from 61-62°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Ba(4), one V(1), and one V(3) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), one V(2), and one V(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(4), one V(2), and one V(4) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(3) atoms. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(1) atoms. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(4) atoms. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(4), and two equivalent V(2) atoms.