NbV3O8 crystallizes in the monoclinic Cm space group. Nb(1) is bonded in a 6-coordinate geometry to one O(5), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. There are three inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing VO6 octahedra. The corner-sharing octahedral tilt angles are 23°. In the second V site, V(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing VO6 octahedra. The corner-sharing octahedral tilt angles are 27°. In the third V site, V(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one V(3) and two equivalent V(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nb(1), one V(1), and one V(3) atom. In the third O site, O(3) is bonded in a linear geometry to one V(1) and one V(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one V(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Nb(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(1) and one V(2) atom. In the seventh O site, O(7) is bonded to one Nb(1), one V(2), and two equivalent V(3) atoms to form distorted corner-sharing ONbV3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Nb(1) and two equivalent V(1) atoms.
NbV3O8 crystallizes in the monoclinic Cm space group. Nb(1) is bonded in a 6-coordinate geometry to one O(5), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. The Nb(1)-O(5) bond length is 1.92 Å. The Nb(1)-O(6) bond length is 1.79 Å. The Nb(1)-O(7) bond length is 2.44 Å. The Nb(1)-O(8) bond length is 2.11 Å. Both Nb(1)-O(2) bond lengths are 1.97 Å. There are three inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing VO6 octahedra. The corner-sharing octahedral tilt angles are 23°. The V(1)-O(2) bond length is 2.08 Å. The V(1)-O(3) bond length is 2.04 Å. The V(1)-O(4) bond length is 1.97 Å. The V(1)-O(5) bond length is 1.90 Å. Both V(1)-O(8) bond lengths are 1.91 Å. In the second V site, V(2) is bonded to one O(4), one O(5), one O(6), one O(7), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing VO6 octahedra. The corner-sharing octahedral tilt angles are 27°. The V(2)-O(4) bond length is 1.91 Å. The V(2)-O(5) bond length is 2.02 Å. The V(2)-O(6) bond length is 1.94 Å. The V(2)-O(7) bond length is 2.11 Å. Both V(2)-O(1) bond lengths are 1.93 Å. In the third V site, V(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(7) atoms. The V(3)-O(1) bond length is 2.03 Å. The V(3)-O(2) bond length is 2.48 Å. The V(3)-O(3) bond length is 1.66 Å. The V(3)-O(4) bond length is 1.96 Å. Both V(3)-O(7) bond lengths are 1.97 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one V(3) and two equivalent V(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nb(1), one V(1), and one V(3) atom. In the third O site, O(3) is bonded in a linear geometry to one V(1) and one V(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one V(3) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Nb(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Nb(1) and one V(2) atom. In the seventh O site, O(7) is bonded to one Nb(1), one V(2), and two equivalent V(3) atoms to form distorted corner-sharing ONbV3 trigonal pyramids. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Nb(1) and two equivalent V(1) atoms.