KNbW2O9 crystallizes in the triclinic P1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to one O(10), one O(13), two equivalent O(22), two equivalent O(25), two equivalent O(5), and two equivalent O(8) atoms. In the second K site, K(2) is bonded in a 12-coordinate geometry to two equivalent O(11), two equivalent O(12), two equivalent O(23), two equivalent O(24), two equivalent O(6), and two equivalent O(7) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(14), one O(15), one O(16), one O(17), one O(18), and one O(19) atom. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(13), one O(14), one O(17), and two equivalent O(20) atoms to form NbO6 octahedra that share  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(4)O6 octahedra,  a cornercorner with one W(5)O6 octahedra, and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-36°. In the second Nb site, Nb(2) is bonded to one O(11), one O(12), one O(15), one O(16), and two equivalent O(21) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-39°. In the third Nb site, Nb(3) is bonded to one O(15), one O(18), one O(22), one O(5), and two equivalent O(1) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(5)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-39°. There are six inequivalent W sites. In the first W site, W(1) is bonded to one O(10), one O(11), one O(5), one O(6), and two equivalent O(26) atoms to form WO6 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 W(4)O6 octahedra, and corners with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-35°. In the second W site, W(2) is bonded to one O(12), one O(13), one O(7), one O(8), and two equivalent O(27) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(5)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-33°. In the third W site, W(3) is bonded to one O(22), one O(23), one O(24), one O(25), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra,  a cornercorner with one W(5)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-34°. In the fourth W site, W(4) is bonded to one O(14), one O(19), one O(23), one O(6), and two equivalent O(2) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-36°. In the fifth W site, W(5) is bonded to one O(17), one O(18), one O(24), one O(7), and two equivalent O(3) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(3)O6 octahedra, and corners with two equivalent W(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-34°. In the sixth W site, W(6) is bonded to one O(16), one O(19), one O(25), one O(8), and two equivalent O(4) atoms to form WO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra, and corners with two equivalent W(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. There are twenty-seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(3) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent W(4) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent W(5) atoms. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent W(6) atoms. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(3), and one W(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(1), and one W(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(2), and one W(5) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to two equivalent K(1), one W(2), and one W(6) atom. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent W(3) atoms. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one K(1), one Nb(1), and one W(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent K(2), one Nb(2), and one W(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to two equivalent K(2), one Nb(2), and one W(2) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one K(1), one Nb(1), and one W(2) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(1), and one W(4) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(2), and one Nb(3) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(2), and one W(6) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(1), and one W(5) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one K(3), one Nb(3), and one W(5) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one K(3), one W(4), and one W(6) atom. In the twentieth O site, O(20) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the twenty-first O site, O(21) is bonded in a linear geometry to two equivalent Nb(2) atoms. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to two equivalent K(1), one Nb(3), and one W(3) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(3), and one W(4) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(3), and one W(5) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to two equivalent K(1), one W(3), and one W(6) atom. In the twenty-sixth O site, O(26) is bonded in a linear geometry to two equivalent W(1) atoms. In the twenty-seventh O site, O(27) is bonded in a linear geometry to two equivalent W(2) atoms.
KNbW2O9 crystallizes in the triclinic P1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to one O(10), one O(13), two equivalent O(22), two equivalent O(25), two equivalent O(5), and two equivalent O(8) atoms. The K(1)-O(10) bond length is 3.40 Å. The K(1)-O(13) bond length is 3.39 Å. There is one shorter (3.27 Å) and one longer (3.38 Å) K(1)-O(22) bond length. There is one shorter (3.32 Å) and one longer (3.42 Å) K(1)-O(25) bond length. There is one shorter (3.23 Å) and one longer (3.34 Å) K(1)-O(5) bond length. There is one shorter (3.34 Å) and one longer (3.45 Å) K(1)-O(8) bond length. In the second K site, K(2) is bonded in a 12-coordinate geometry to two equivalent O(11), two equivalent O(12), two equivalent O(23), two equivalent O(24), two equivalent O(6), and two equivalent O(7) atoms. There is one shorter (3.35 Å) and one longer (3.47 Å) K(2)-O(11) bond length. There is one shorter (3.38 Å) and one longer (3.49 Å) K(2)-O(12) bond length. There is one shorter (3.30 Å) and one longer (3.42 Å) K(2)-O(23) bond length. There is one shorter (3.27 Å) and one longer (3.37 Å) K(2)-O(24) bond length. There is one shorter (3.30 Å) and one longer (3.43 Å) K(2)-O(6) bond length. There is one shorter (3.32 Å) and one longer (3.43 Å) K(2)-O(7) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(14), one O(15), one O(16), one O(17), one O(18), and one O(19) atom. The K(3)-O(14) bond length is 3.15 Å. The K(3)-O(15) bond length is 3.06 Å. The K(3)-O(16) bond length is 3.17 Å. The K(3)-O(17) bond length is 3.17 Å. The K(3)-O(18) bond length is 3.29 Å. The K(3)-O(19) bond length is 3.29 Å. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(13), one O(14), one O(17), and two equivalent O(20) atoms to form NbO6 octahedra that share  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(4)O6 octahedra,  a cornercorner with one W(5)O6 octahedra, and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-36°. The Nb(1)-O(10) bond length is 1.97 Å. The Nb(1)-O(13) bond length is 1.97 Å. The Nb(1)-O(14) bond length is 2.09 Å. The Nb(1)-O(17) bond length is 2.06 Å. There is one shorter (1.83 Å) and one longer (2.13 Å) Nb(1)-O(20) bond length. In the second Nb site, Nb(2) is bonded to one O(11), one O(12), one O(15), one O(16), and two equivalent O(21) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-39°. The Nb(2)-O(11) bond length is 2.01 Å. The Nb(2)-O(12) bond length is 2.07 Å. The Nb(2)-O(15) bond length is 1.97 Å. The Nb(2)-O(16) bond length is 2.06 Å. There is one shorter (1.83 Å) and one longer (2.13 Å) Nb(2)-O(21) bond length. In the third Nb site, Nb(3) is bonded to one O(15), one O(18), one O(22), one O(5), and two equivalent O(1) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(5)O6 octahedra, and corners with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-39°. The Nb(3)-O(15) bond length is 1.97 Å. The Nb(3)-O(18) bond length is 2.00 Å. The Nb(3)-O(22) bond length is 2.06 Å. The Nb(3)-O(5) bond length is 2.05 Å. There is one shorter (1.83 Å) and one longer (2.13 Å) Nb(3)-O(1) bond length. There are six inequivalent W sites. In the first W site, W(1) is bonded to one O(10), one O(11), one O(5), one O(6), and two equivalent O(26) atoms to form WO6 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 W(4)O6 octahedra, and corners with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-35°. The W(1)-O(10) bond length is 1.93 Å. The W(1)-O(11) bond length is 1.92 Å. The W(1)-O(5) bond length is 1.89 Å. The W(1)-O(6) bond length is 2.00 Å. There is one shorter (1.84 Å) and one longer (2.12 Å) W(1)-O(26) bond length. In the second W site, W(2) is bonded to one O(12), one O(13), one O(7), one O(8), and two equivalent O(27) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(5)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-33°. The W(2)-O(12) bond length is 1.88 Å. The W(2)-O(13) bond length is 1.96 Å. The W(2)-O(7) bond length is 1.94 Å. The W(2)-O(8) bond length is 1.97 Å. There is one shorter (1.84 Å) and one longer (2.12 Å) W(2)-O(27) bond length. In the third W site, W(3) is bonded to one O(22), one O(23), one O(24), one O(25), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra,  a cornercorner with one W(5)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-34°. The W(3)-O(22) bond length is 1.89 Å. The W(3)-O(23) bond length is 1.96 Å. The W(3)-O(24) bond length is 1.94 Å. The W(3)-O(25) bond length is 1.95 Å. There is one shorter (1.84 Å) and one longer (2.12 Å) W(3)-O(9) bond length. In the fourth W site, W(4) is bonded to one O(14), one O(19), one O(23), one O(6), and two equivalent O(2) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(6)O6 octahedra, and corners with two equivalent W(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-36°. The W(4)-O(14) bond length is 1.88 Å. The W(4)-O(19) bond length is 1.96 Å. The W(4)-O(23) bond length is 1.97 Å. The W(4)-O(6) bond length is 1.92 Å. There is one shorter (1.84 Å) and one longer (2.11 Å) W(4)-O(2) bond length. In the fifth W site, W(5) is bonded to one O(17), one O(18), one O(24), one O(7), and two equivalent O(3) atoms to form WO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(3)O6 octahedra, and corners with two equivalent W(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-34°. The W(5)-O(17) bond length is 1.88 Å. The W(5)-O(18) bond length is 1.89 Å. The W(5)-O(24) bond length is 1.99 Å. The W(5)-O(7) bond length is 1.98 Å. There is one shorter (1.84 Å) and one longer (2.11 Å) W(5)-O(3) bond length. In the sixth W site, W(6) is bonded to one O(16), one O(19), one O(25), one O(8), and two equivalent O(4) atoms to form WO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra, and corners with two equivalent W(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-33°. The W(6)-O(16) bond length is 1.88 Å. The W(6)-O(19) bond length is 1.93 Å. The W(6)-O(25) bond length is 1.97 Å. The W(6)-O(8) bond length is 1.95 Å. There is one shorter (1.84 Å) and one longer (2.11 Å) W(6)-O(4) bond length. There are twenty-seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Nb(3) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent W(4) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent W(5) atoms. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent W(6) atoms. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(3), and one W(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(1), and one W(4) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(2), and one W(5) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to two equivalent K(1), one W(2), and one W(6) atom. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent W(3) atoms. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one K(1), one Nb(1), and one W(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent K(2), one Nb(2), and one W(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to two equivalent K(2), one Nb(2), and one W(2) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one K(1), one Nb(1), and one W(2) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(1), and one W(4) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(2), and one Nb(3) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(2), and one W(6) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one K(3), one Nb(1), and one W(5) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one K(3), one Nb(3), and one W(5) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one K(3), one W(4), and one W(6) atom. In the twentieth O site, O(20) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the twenty-first O site, O(21) is bonded in a linear geometry to two equivalent Nb(2) atoms. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to two equivalent K(1), one Nb(3), and one W(3) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(3), and one W(4) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(3), and one W(5) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to two equivalent K(1), one W(3), and one W(6) atom. In the twenty-sixth O site, O(26) is bonded in a linear geometry to two equivalent W(1) atoms. In the twenty-seventh O site, O(27) is bonded in a linear geometry to two equivalent W(2) atoms.