Nb6(Pb2O5)5 crystallizes in the monoclinic Pm space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(10), one O(16), one O(17), one O(6), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Pb(1)O6 octahedra,  a cornercorner with one Pb(2)O6 octahedra, and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-58°. In the second Nb site, Nb(2) is bonded to one O(2), one O(7), two equivalent O(10), and two equivalent O(11) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Pb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(13), one O(3), one O(4), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Pb(1)O6 octahedra,  a cornercorner with one Pb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-65°. In the fourth Nb site, Nb(4) is bonded to one O(15), one O(8), two equivalent O(4), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Pb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-73°. There are eight inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to one O(2), one O(7), two equivalent O(16), and two equivalent O(5) atoms to form PbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-60°. In the second Pb site, Pb(2) is bonded to one O(15), one O(8), two equivalent O(1), and two equivalent O(12) atoms to form PbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-73°. In the third Pb site, Pb(3) is bonded in a 4-coordinate geometry to one O(1), one O(14), one O(15), and one O(16) atom. In the fourth Pb site, Pb(4) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(4) atoms. In the fifth Pb site, Pb(5) is bonded in a distorted square co-planar geometry to one O(12), one O(5), one O(7), and one O(8) atom. In the sixth Pb site, Pb(6) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(12) atoms. In the seventh Pb site, Pb(7) is bonded in a 4-coordinate geometry to one O(14), one O(9), and two equivalent O(10) atoms. In the eighth Pb site, Pb(8) is bonded in a 6-coordinate geometry to one O(14), one O(9), two equivalent O(16), and two equivalent O(5) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Nb(1), one Pb(2), one Pb(3), and one Pb(6) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Nb(2) and one Pb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(3) and one Pb(4) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(3), one Nb(4), and one Pb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Nb(3), one Pb(1), one Pb(5), and one Pb(8) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(4) atom. In the seventh O site, O(7) is bonded to one Nb(2), one Pb(1), and two equivalent Pb(5) atoms to form distorted corner-sharing ONbPb3 tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Nb(4), one Pb(2), and two equivalent Pb(5) atoms. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Nb(1), one Pb(7), and one Pb(8) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one Pb(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one Nb(3) atom. In the twelfth O site, O(12) is bonded to one Nb(3), one Pb(2), one Pb(5), and one Pb(6) atom to form distorted corner-sharing ONbPb3 tetrahedra. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent Nb(3) atoms. In the fourteenth O site, O(14) is bonded to one Pb(7), one Pb(8), and two equivalent Pb(3) atoms to form edge-sharing OPb4 tetrahedra. In the fifteenth O site, O(15) is bonded to one Nb(4), one Pb(2), and two equivalent Pb(3) atoms to form distorted ONbPb3 tetrahedra that share corners with two equivalent O(12)NbPb3 tetrahedra, corners with two equivalent O(16)NbPb3 tetrahedra, and  an edgeedge with one O(14)Pb4 tetrahedra. In the sixteenth O site, O(16) is bonded to one Nb(1), one Pb(1), one Pb(3), and one Pb(8) atom to form distorted ONbPb3 tetrahedra that share  a cornercorner with one O(15)NbPb3 tetrahedra,  a cornercorner with one O(7)NbPb3 tetrahedra, corners with two equivalent O(16)NbPb3 tetrahedra, and  an edgeedge with one O(14)Pb4 tetrahedra. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms.
Nb6(Pb2O5)5 crystallizes in the monoclinic Pm space group. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(10), one O(16), one O(17), one O(6), and one O(9) atom to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Pb(1)O6 octahedra,  a cornercorner with one Pb(2)O6 octahedra, and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-58°. The Nb(1)-O(1) bond length is 1.91 Å. The Nb(1)-O(10) bond length is 2.19 Å. The Nb(1)-O(16) bond length is 2.16 Å. The Nb(1)-O(17) bond length is 1.97 Å. The Nb(1)-O(6) bond length is 1.91 Å. The Nb(1)-O(9) bond length is 2.07 Å. In the second Nb site, Nb(2) is bonded to one O(2), one O(7), two equivalent O(10), and two equivalent O(11) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Pb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-60°. The Nb(2)-O(2) bond length is 1.95 Å. The Nb(2)-O(7) bond length is 2.14 Å. Both Nb(2)-O(10) bond lengths are 1.92 Å. Both Nb(2)-O(11) bond lengths are 2.13 Å. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(13), one O(3), one O(4), and one O(5) atom to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Pb(1)O6 octahedra,  a cornercorner with one Pb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-65°. The Nb(3)-O(11) bond length is 1.91 Å. The Nb(3)-O(12) bond length is 2.03 Å. The Nb(3)-O(13) bond length is 1.99 Å. The Nb(3)-O(3) bond length is 2.05 Å. The Nb(3)-O(4) bond length is 2.18 Å. The Nb(3)-O(5) bond length is 2.00 Å. In the fourth Nb site, Nb(4) is bonded to one O(15), one O(8), two equivalent O(4), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Pb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-73°. The Nb(4)-O(15) bond length is 2.05 Å. The Nb(4)-O(8) bond length is 1.93 Å. Both Nb(4)-O(4) bond lengths are 1.95 Å. Both Nb(4)-O(6) bond lengths are 2.16 Å. There are eight inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to one O(2), one O(7), two equivalent O(16), and two equivalent O(5) atoms to form PbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-60°. The Pb(1)-O(2) bond length is 2.24 Å. The Pb(1)-O(7) bond length is 2.28 Å. Both Pb(1)-O(16) bond lengths are 2.22 Å. Both Pb(1)-O(5) bond lengths are 2.25 Å. In the second Pb site, Pb(2) is bonded to one O(15), one O(8), two equivalent O(1), and two equivalent O(12) atoms to form PbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and corners with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-73°. The Pb(2)-O(15) bond length is 2.60 Å. The Pb(2)-O(8) bond length is 2.45 Å. Both Pb(2)-O(1) bond lengths are 2.51 Å. Both Pb(2)-O(12) bond lengths are 2.54 Å. In the third Pb site, Pb(3) is bonded in a 4-coordinate geometry to one O(1), one O(14), one O(15), and one O(16) atom. The Pb(3)-O(1) bond length is 2.60 Å. The Pb(3)-O(14) bond length is 2.40 Å. The Pb(3)-O(15) bond length is 2.37 Å. The Pb(3)-O(16) bond length is 2.62 Å. In the fourth Pb site, Pb(4) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(4) atoms. The Pb(4)-O(3) bond length is 2.41 Å. Both Pb(4)-O(4) bond lengths are 2.62 Å. In the fifth Pb site, Pb(5) is bonded in a distorted square co-planar geometry to one O(12), one O(5), one O(7), and one O(8) atom. The Pb(5)-O(12) bond length is 2.48 Å. The Pb(5)-O(5) bond length is 2.68 Å. The Pb(5)-O(7) bond length is 2.54 Å. The Pb(5)-O(8) bond length is 2.68 Å. In the sixth Pb site, Pb(6) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(12) atoms. Both Pb(6)-O(1) bond lengths are 2.74 Å. Both Pb(6)-O(12) bond lengths are 2.38 Å. In the seventh Pb site, Pb(7) is bonded in a 4-coordinate geometry to one O(14), one O(9), and two equivalent O(10) atoms. The Pb(7)-O(14) bond length is 2.27 Å. The Pb(7)-O(9) bond length is 2.61 Å. Both Pb(7)-O(10) bond lengths are 2.63 Å. In the eighth Pb site, Pb(8) is bonded in a 6-coordinate geometry to one O(14), one O(9), two equivalent O(16), and two equivalent O(5) atoms. The Pb(8)-O(14) bond length is 2.39 Å. The Pb(8)-O(9) bond length is 2.78 Å. Both Pb(8)-O(16) bond lengths are 2.49 Å. Both Pb(8)-O(5) bond lengths are 2.79 Å. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Nb(1), one Pb(2), one Pb(3), and one Pb(6) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Nb(2) and one Pb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(3) and one Pb(4) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(3), one Nb(4), and one Pb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Nb(3), one Pb(1), one Pb(5), and one Pb(8) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(4) atom. In the seventh O site, O(7) is bonded to one Nb(2), one Pb(1), and two equivalent Pb(5) atoms to form distorted corner-sharing ONbPb3 tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Nb(4), one Pb(2), and two equivalent Pb(5) atoms. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Nb(1), one Pb(7), and one Pb(8) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one Pb(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one Nb(3) atom. In the twelfth O site, O(12) is bonded to one Nb(3), one Pb(2), one Pb(5), and one Pb(6) atom to form distorted corner-sharing ONbPb3 tetrahedra. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent Nb(3) atoms. In the fourteenth O site, O(14) is bonded to one Pb(7), one Pb(8), and two equivalent Pb(3) atoms to form edge-sharing OPb4 tetrahedra. In the fifteenth O site, O(15) is bonded to one Nb(4), one Pb(2), and two equivalent Pb(3) atoms to form distorted ONbPb3 tetrahedra that share corners with two equivalent O(12)NbPb3 tetrahedra, corners with two equivalent O(16)NbPb3 tetrahedra, and  an edgeedge with one O(14)Pb4 tetrahedra. In the sixteenth O site, O(16) is bonded to one Nb(1), one Pb(1), one Pb(3), and one Pb(8) atom to form distorted ONbPb3 tetrahedra that share  a cornercorner with one O(15)NbPb3 tetrahedra,  a cornercorner with one O(7)NbPb3 tetrahedra, corners with two equivalent O(16)NbPb3 tetrahedra, and  an edgeedge with one O(14)Pb4 tetrahedra. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to two equivalent Nb(1) atoms.