K6Nb11O30 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(11), and two equivalent O(2) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(13), two equivalent O(9), and four equivalent O(3) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one O(13), two equivalent O(10), and four equivalent O(4) atoms. In the fourth K site, K(4) is bonded to one O(6), one O(7), one O(8), two equivalent O(14), two equivalent O(15), two equivalent O(16), and two equivalent O(17) atoms to form distorted KO11 cuboctahedra that share edges with two equivalent Nb(1)O6 octahedra, faces with two equivalent K(4)O11 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Nb(4)O6 octahedra. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(14), one O(17), one O(2), one O(9), and two equivalent O(5) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and edges with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-29°. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(15), one O(16), and two equivalent O(6) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-23°. In the third Nb site, Nb(3) is bonded to one O(11), one O(15), one O(17), one O(3), and two equivalent O(8) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-37°. In the fourth Nb site, Nb(4) is bonded to one O(11), one O(14), one O(16), one O(4), and two equivalent O(7) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-37°. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(12), and two equivalent O(2) atoms. In the sixth Nb site, Nb(6) is bonded to two equivalent O(13), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 13-35°. In the seventh Nb site, Nb(7) is bonded in a 9-coordinate geometry to one O(12), two equivalent O(5), two equivalent O(9), and four equivalent O(2) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent K(1), one Nb(2), and one Nb(5) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent K(1), one Nb(1), one Nb(5), and two equivalent Nb(7) atoms. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Nb(3), and one Nb(6) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(3), one Nb(4), and one Nb(6) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Nb(7) and two equivalent Nb(1) atoms. In the sixth O site, O(6) is bonded in a distorted linear geometry to one K(4) and two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one K(4) and two equivalent Nb(4) atoms. In the eighth O site, O(8) is bonded in a distorted linear geometry to one K(4) and two equivalent Nb(3) atoms. In the ninth O site, O(9) is bonded to two equivalent K(2), two equivalent Nb(1), and two equivalent Nb(7) atoms to form distorted edge-sharing OK2Nb4 octahedra. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to two equivalent K(3) and two equivalent Nb(2) atoms. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent K(1), one Nb(3), and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Nb(7) and two equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded in a distorted linear geometry to one K(2), one K(3), and two equivalent Nb(6) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to two equivalent K(4), one Nb(1), and one Nb(4) atom. In the fifteenth O site, O(15) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(2), and one Nb(3) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(2), and one Nb(4) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(1), and one Nb(3) atom.
K6Nb11O30 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(11), and two equivalent O(2) atoms. Both K(1)-O(1) bond lengths are 2.97 Å. Both K(1)-O(11) bond lengths are 2.80 Å. Both K(1)-O(2) bond lengths are 3.26 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(13), two equivalent O(9), and four equivalent O(3) atoms. The K(2)-O(13) bond length is 3.07 Å. Both K(2)-O(9) bond lengths are 3.12 Å. All K(2)-O(3) bond lengths are 2.91 Å. In the third K site, K(3) is bonded in a 7-coordinate geometry to one O(13), two equivalent O(10), and four equivalent O(4) atoms. The K(3)-O(13) bond length is 3.11 Å. Both K(3)-O(10) bond lengths are 2.96 Å. All K(3)-O(4) bond lengths are 2.95 Å. In the fourth K site, K(4) is bonded to one O(6), one O(7), one O(8), two equivalent O(14), two equivalent O(15), two equivalent O(16), and two equivalent O(17) atoms to form distorted KO11 cuboctahedra that share edges with two equivalent Nb(1)O6 octahedra, faces with two equivalent K(4)O11 cuboctahedra, faces with two equivalent Nb(2)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Nb(4)O6 octahedra. The K(4)-O(6) bond length is 2.77 Å. The K(4)-O(7) bond length is 2.86 Å. The K(4)-O(8) bond length is 2.86 Å. Both K(4)-O(14) bond lengths are 2.92 Å. Both K(4)-O(15) bond lengths are 2.80 Å. Both K(4)-O(16) bond lengths are 2.79 Å. Both K(4)-O(17) bond lengths are 2.92 Å. There are seven inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(14), one O(17), one O(2), one O(9), and two equivalent O(5) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and edges with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-29°. The Nb(1)-O(14) bond length is 1.85 Å. The Nb(1)-O(17) bond length is 1.84 Å. The Nb(1)-O(2) bond length is 2.19 Å. The Nb(1)-O(9) bond length is 2.19 Å. Both Nb(1)-O(5) bond lengths are 2.05 Å. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(15), one O(16), and two equivalent O(6) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-23°. The Nb(2)-O(1) bond length is 2.17 Å. The Nb(2)-O(10) bond length is 2.01 Å. The Nb(2)-O(15) bond length is 2.14 Å. The Nb(2)-O(16) bond length is 1.92 Å. Both Nb(2)-O(6) bond lengths are 1.99 Å. In the third Nb site, Nb(3) is bonded to one O(11), one O(15), one O(17), one O(3), and two equivalent O(8) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-37°. The Nb(3)-O(11) bond length is 1.94 Å. The Nb(3)-O(15) bond length is 1.96 Å. The Nb(3)-O(17) bond length is 2.27 Å. The Nb(3)-O(3) bond length is 2.07 Å. Both Nb(3)-O(8) bond lengths are 1.99 Å. In the fourth Nb site, Nb(4) is bonded to one O(11), one O(14), one O(16), one O(4), and two equivalent O(7) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one Nb(6)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and faces with two equivalent K(4)O11 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-37°. The Nb(4)-O(11) bond length is 2.06 Å. The Nb(4)-O(14) bond length is 2.30 Å. The Nb(4)-O(16) bond length is 2.10 Å. The Nb(4)-O(4) bond length is 1.84 Å. Both Nb(4)-O(7) bond lengths are 2.00 Å. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(12), and two equivalent O(2) atoms. Both Nb(5)-O(1) bond lengths are 1.84 Å. Both Nb(5)-O(12) bond lengths are 2.04 Å. Both Nb(5)-O(2) bond lengths are 2.19 Å. In the sixth Nb site, Nb(6) is bonded to two equivalent O(13), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 13-35°. Both Nb(6)-O(13) bond lengths are 1.99 Å. Both Nb(6)-O(3) bond lengths are 1.91 Å. Both Nb(6)-O(4) bond lengths are 2.17 Å. In the seventh Nb site, Nb(7) is bonded in a 9-coordinate geometry to one O(12), two equivalent O(5), two equivalent O(9), and four equivalent O(2) atoms. The Nb(7)-O(12) bond length is 2.02 Å. Both Nb(7)-O(5) bond lengths are 2.01 Å. Both Nb(7)-O(9) bond lengths are 2.53 Å. All Nb(7)-O(2) bond lengths are 2.43 Å. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent K(1), one Nb(2), and one Nb(5) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent K(1), one Nb(1), one Nb(5), and two equivalent Nb(7) atoms. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Nb(3), and one Nb(6) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent K(3), one Nb(4), and one Nb(6) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Nb(7) and two equivalent Nb(1) atoms. In the sixth O site, O(6) is bonded in a distorted linear geometry to one K(4) and two equivalent Nb(2) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one K(4) and two equivalent Nb(4) atoms. In the eighth O site, O(8) is bonded in a distorted linear geometry to one K(4) and two equivalent Nb(3) atoms. In the ninth O site, O(9) is bonded to two equivalent K(2), two equivalent Nb(1), and two equivalent Nb(7) atoms to form distorted edge-sharing OK2Nb4 octahedra. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to two equivalent K(3) and two equivalent Nb(2) atoms. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent K(1), one Nb(3), and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Nb(7) and two equivalent Nb(5) atoms. In the thirteenth O site, O(13) is bonded in a distorted linear geometry to one K(2), one K(3), and two equivalent Nb(6) atoms. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to two equivalent K(4), one Nb(1), and one Nb(4) atom. In the fifteenth O site, O(15) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(2), and one Nb(3) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(2), and one Nb(4) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to two equivalent K(4), one Nb(1), and one Nb(3) atom.