K6Ta11O30 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), and four equivalent O(8) atoms. In the second K site, K(2) is bonded in a 13-coordinate geometry to one O(5), two equivalent O(15), two equivalent O(2), four equivalent O(11), and four equivalent O(9) atoms. In the third K site, K(3) is bonded in a 11-coordinate geometry to one O(16), one O(17), one O(4), two equivalent O(12), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. In the fourth K site, K(4) is bonded to one O(14), one O(15), one O(16), one O(17), two equivalent O(10), two equivalent O(11), two equivalent O(12), and two equivalent O(13) atoms to form distorted KO12 cuboctahedra that share faces with two equivalent K(4)O12 cuboctahedra, faces with two equivalent Ta(1)O6 octahedra, faces with two equivalent Ta(2)O6 octahedra, faces with two equivalent Ta(3)O6 octahedra, and faces with two equivalent Ta(4)O6 octahedra. There are seven inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(10), one O(13), one O(6), and two equivalent O(14) atoms to form distorted TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(5)O6 octahedra, corners with three equivalent Ta(1)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 4-27°. In the second Ta site, Ta(2) is bonded to one O(11), one O(12), one O(2), one O(7), and two equivalent O(15) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(5)O6 octahedra, corners with three equivalent Ta(2)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-39°. In the third Ta site, Ta(3) is bonded to one O(10), one O(12), one O(3), one O(8), and two equivalent O(16) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-35°. In the fourth Ta site, Ta(4) is bonded to one O(11), one O(13), one O(3), one O(9), and two equivalent O(17) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 4-35°. In the fifth Ta site, Ta(5) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 10-39°. In the sixth Ta site, Ta(6) is bonded to two equivalent O(5), two equivalent O(8), and two equivalent O(9) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 6-32°. In the seventh Ta site, Ta(7) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(14), and four equivalent O(6) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded to two equivalent K(1), two equivalent Ta(1), and two equivalent Ta(7) atoms to form distorted edge-sharing OK2Ta4 octahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2) and two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(3), one Ta(3), and one Ta(4) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent K(3), one Ta(7), and two equivalent Ta(5) atoms. In the fifth O site, O(5) is bonded in a distorted linear geometry to one K(1), one K(2), and two equivalent Ta(6) atoms. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(3), one Ta(1), one Ta(5), and two equivalent Ta(7) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent K(3), one Ta(2), and one Ta(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(3), and one Ta(6) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(4), and one Ta(6) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to two equivalent K(4), one Ta(1), and one Ta(3) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to two equivalent K(2), two equivalent K(4), one Ta(2), and one Ta(4) atom. In the twelfth O site, O(12) is bonded in a distorted linear geometry to two equivalent K(3), two equivalent K(4), one Ta(2), and one Ta(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent K(4), one Ta(1), and one Ta(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one K(4), one Ta(7), and two equivalent Ta(1) atoms. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one K(2), one K(4), and two equivalent Ta(2) atoms. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one K(3), one K(4), and two equivalent Ta(3) atoms. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one K(3), one K(4), and two equivalent Ta(4) atoms.
K6Ta11O30 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), and four equivalent O(8) atoms. The K(1)-O(5) bond length is 2.96 Å. Both K(1)-O(1) bond lengths are 3.08 Å. All K(1)-O(8) bond lengths are 2.88 Å. In the second K site, K(2) is bonded in a 13-coordinate geometry to one O(5), two equivalent O(15), two equivalent O(2), four equivalent O(11), and four equivalent O(9) atoms. The K(2)-O(5) bond length is 3.12 Å. Both K(2)-O(15) bond lengths are 3.32 Å. Both K(2)-O(2) bond lengths are 2.96 Å. All K(2)-O(11) bond lengths are 3.38 Å. All K(2)-O(9) bond lengths are 2.95 Å. In the third K site, K(3) is bonded in a 11-coordinate geometry to one O(16), one O(17), one O(4), two equivalent O(12), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. The K(3)-O(16) bond length is 3.07 Å. The K(3)-O(17) bond length is 3.18 Å. The K(3)-O(4) bond length is 3.30 Å. Both K(3)-O(12) bond lengths are 3.25 Å. Both K(3)-O(3) bond lengths are 2.75 Å. Both K(3)-O(6) bond lengths are 3.29 Å. Both K(3)-O(7) bond lengths are 2.97 Å. In the fourth K site, K(4) is bonded to one O(14), one O(15), one O(16), one O(17), two equivalent O(10), two equivalent O(11), two equivalent O(12), and two equivalent O(13) atoms to form distorted KO12 cuboctahedra that share faces with two equivalent K(4)O12 cuboctahedra, faces with two equivalent Ta(1)O6 octahedra, faces with two equivalent Ta(2)O6 octahedra, faces with two equivalent Ta(3)O6 octahedra, and faces with two equivalent Ta(4)O6 octahedra. The K(4)-O(14) bond length is 3.27 Å. The K(4)-O(15) bond length is 2.71 Å. The K(4)-O(16) bond length is 2.80 Å. The K(4)-O(17) bond length is 2.82 Å. Both K(4)-O(10) bond lengths are 2.89 Å. Both K(4)-O(11) bond lengths are 2.78 Å. Both K(4)-O(12) bond lengths are 2.78 Å. Both K(4)-O(13) bond lengths are 2.91 Å. There are seven inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(10), one O(13), one O(6), and two equivalent O(14) atoms to form distorted TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(5)O6 octahedra, corners with three equivalent Ta(1)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 4-27°. The Ta(1)-O(1) bond length is 2.15 Å. The Ta(1)-O(10) bond length is 1.85 Å. The Ta(1)-O(13) bond length is 1.86 Å. The Ta(1)-O(6) bond length is 2.13 Å. Both Ta(1)-O(14) bond lengths are 2.04 Å. In the second Ta site, Ta(2) is bonded to one O(11), one O(12), one O(2), one O(7), and two equivalent O(15) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(5)O6 octahedra, corners with three equivalent Ta(2)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-39°. The Ta(2)-O(11) bond length is 1.94 Å. The Ta(2)-O(12) bond length is 2.06 Å. The Ta(2)-O(2) bond length is 2.00 Å. The Ta(2)-O(7) bond length is 2.10 Å. Both Ta(2)-O(15) bond lengths are 1.98 Å. In the third Ta site, Ta(3) is bonded to one O(10), one O(12), one O(3), one O(8), and two equivalent O(16) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-35°. The Ta(3)-O(10) bond length is 2.19 Å. The Ta(3)-O(12) bond length is 2.00 Å. The Ta(3)-O(3) bond length is 1.94 Å. The Ta(3)-O(8) bond length is 1.99 Å. Both Ta(3)-O(16) bond lengths are 1.99 Å. In the fourth Ta site, Ta(4) is bonded to one O(11), one O(13), one O(3), one O(9), and two equivalent O(17) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, and faces with two equivalent K(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 4-35°. The Ta(4)-O(11) bond length is 2.04 Å. The Ta(4)-O(13) bond length is 2.22 Å. The Ta(4)-O(3) bond length is 2.04 Å. The Ta(4)-O(9) bond length is 1.86 Å. Both Ta(4)-O(17) bond lengths are 2.00 Å. In the fifth Ta site, Ta(5) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 10-39°. Both Ta(5)-O(4) bond lengths are 2.01 Å. Both Ta(5)-O(6) bond lengths are 2.16 Å. Both Ta(5)-O(7) bond lengths are 1.84 Å. In the sixth Ta site, Ta(6) is bonded to two equivalent O(5), two equivalent O(8), and two equivalent O(9) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 6-32°. Both Ta(6)-O(5) bond lengths are 1.98 Å. Both Ta(6)-O(8) bond lengths are 1.95 Å. Both Ta(6)-O(9) bond lengths are 2.07 Å. In the seventh Ta site, Ta(7) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(14), and four equivalent O(6) atoms. The Ta(7)-O(4) bond length is 2.02 Å. Both Ta(7)-O(1) bond lengths are 2.60 Å. Both Ta(7)-O(14) bond lengths are 2.02 Å. All Ta(7)-O(6) bond lengths are 2.41 Å. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded to two equivalent K(1), two equivalent Ta(1), and two equivalent Ta(7) atoms to form distorted edge-sharing OK2Ta4 octahedra. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2) and two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(3), one Ta(3), and one Ta(4) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent K(3), one Ta(7), and two equivalent Ta(5) atoms. In the fifth O site, O(5) is bonded in a distorted linear geometry to one K(1), one K(2), and two equivalent Ta(6) atoms. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(3), one Ta(1), one Ta(5), and two equivalent Ta(7) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent K(3), one Ta(2), and one Ta(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(3), and one Ta(6) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(4), and one Ta(6) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to two equivalent K(4), one Ta(1), and one Ta(3) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to two equivalent K(2), two equivalent K(4), one Ta(2), and one Ta(4) atom. In the twelfth O site, O(12) is bonded in a distorted linear geometry to two equivalent K(3), two equivalent K(4), one Ta(2), and one Ta(3) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent K(4), one Ta(1), and one Ta(4) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one K(4), one Ta(7), and two equivalent Ta(1) atoms. In the fifteenth O site, O(15) is bonded in a distorted linear geometry to one K(2), one K(4), and two equivalent Ta(2) atoms. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one K(3), one K(4), and two equivalent Ta(3) atoms. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one K(3), one K(4), and two equivalent Ta(4) atoms.