KTaW2O9 crystallizes in the triclinic P1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(15), one O(9), two equivalent O(1), two equivalent O(11), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(16), two equivalent O(13), two equivalent O(2), and two equivalent O(3) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(17), one O(18), one O(19), one O(20), one O(21), and one O(22) atom. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(17), one O(20), one O(4), and two equivalent O(15) atoms to form TaO6 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 Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-36°. In the second Ta site, Ta(2) is bonded to one O(18), one O(19), one O(2), one O(3), and two equivalent O(16) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(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 Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-35°. In the third Ta site, Ta(3) is bonded to one O(11), one O(18), one O(21), one O(23), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(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 Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-35°. There are six inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(11), one O(12), one O(2), and two equivalent O(9) atoms to form distorted WO6 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 W(4)O6 octahedra, and corners with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-35°. In the second W site, W(2) is bonded to one O(13), one O(14), one O(3), one O(4), and two equivalent O(10) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(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 0-32°. In the third W site, W(3) is bonded to one O(23), one O(24), one O(25), one O(26), and two equivalent O(27) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 4-33°. In the fourth W site, W(4) is bonded to one O(12), one O(17), one O(22), one O(24), and two equivalent O(6) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 1-36°. In the fifth W site, W(5) is bonded to one O(13), one O(20), one O(21), one O(25), and two equivalent O(7) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(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 5-33°. In the sixth W site, W(6) is bonded to one O(14), one O(19), one O(22), one O(26), and two equivalent O(8) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 1-33°. There are twenty-seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one W(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(2), and one W(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(2), and one W(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ta(3) atoms. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent W(4) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent W(5) atoms. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent W(6) atoms. In the ninth O site, O(9) is bonded in a distorted linear geometry to one K(1) and two equivalent W(1) atoms. In the tenth O site, O(10) is bonded in a distorted linear geometry to two equivalent W(2) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(3), and one W(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one W(1) and one W(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(2), and one W(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one W(2) and one W(6) atom. In the fifteenth O site, O(15) is bonded in a linear geometry to one K(1) and two equivalent Ta(1) atoms. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one K(2) and two equivalent Ta(2) atoms. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one K(3), one Ta(1), and one W(4) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(2), and one Ta(3) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(2), and one W(6) atom. In the twentieth O site, O(20) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(1), and one W(5) atom. In the twenty-first O site, O(21) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(3), and one W(5) atom. In the twenty-second O site, O(22) is bonded in a distorted bent 150 degrees geometry to one K(3), one W(4), and one W(6) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Ta(3) and one W(3) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to one W(3) and one W(4) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to one W(3) and one W(5) atom. In the twenty-sixth O site, O(26) is bonded in a bent 150 degrees geometry to one W(3) and one W(6) atom. In the twenty-seventh O site, O(27) is bonded in a linear geometry to two equivalent W(3) atoms.
KTaW2O9 crystallizes in the triclinic P1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(15), one O(9), two equivalent O(1), two equivalent O(11), and two equivalent O(4) atoms. The K(1)-O(15) bond length is 3.24 Å. The K(1)-O(9) bond length is 3.26 Å. There is one shorter (2.88 Å) and one longer (2.97 Å) K(1)-O(1) bond length. There is one shorter (3.07 Å) and one longer (3.15 Å) K(1)-O(11) bond length. There is one shorter (3.09 Å) and one longer (3.18 Å) K(1)-O(4) bond length. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(16), two equivalent O(13), two equivalent O(2), and two equivalent O(3) atoms. The K(2)-O(16) bond length is 3.01 Å. There is one shorter (3.29 Å) and one longer (3.31 Å) K(2)-O(13) bond length. There is one shorter (2.95 Å) and one longer (2.98 Å) K(2)-O(2) bond length. There is one shorter (2.89 Å) and one longer (2.91 Å) K(2)-O(3) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(17), one O(18), one O(19), one O(20), one O(21), and one O(22) atom. The K(3)-O(17) bond length is 2.86 Å. The K(3)-O(18) bond length is 2.86 Å. The K(3)-O(19) bond length is 2.94 Å. The K(3)-O(20) bond length is 2.94 Å. The K(3)-O(21) bond length is 3.03 Å. The K(3)-O(22) bond length is 2.96 Å. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(17), one O(20), one O(4), and two equivalent O(15) atoms to form TaO6 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 Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-36°. The Ta(1)-O(1) bond length is 1.96 Å. The Ta(1)-O(17) bond length is 1.98 Å. The Ta(1)-O(20) bond length is 2.00 Å. The Ta(1)-O(4) bond length is 2.00 Å. There is one shorter (1.87 Å) and one longer (2.06 Å) Ta(1)-O(15) bond length. In the second Ta site, Ta(2) is bonded to one O(18), one O(19), one O(2), one O(3), and two equivalent O(16) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(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 Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-35°. The Ta(2)-O(18) bond length is 1.93 Å. The Ta(2)-O(19) bond length is 1.96 Å. The Ta(2)-O(2) bond length is 2.03 Å. The Ta(2)-O(3) bond length is 2.03 Å. There is one shorter (1.88 Å) and one longer (2.06 Å) Ta(2)-O(16) bond length. In the third Ta site, Ta(3) is bonded to one O(11), one O(18), one O(21), one O(23), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(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 Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-35°. The Ta(3)-O(11) bond length is 2.00 Å. The Ta(3)-O(18) bond length is 1.94 Å. The Ta(3)-O(21) bond length is 1.98 Å. The Ta(3)-O(23) bond length is 2.03 Å. There is one shorter (1.86 Å) and one longer (2.08 Å) Ta(3)-O(5) bond length. There are six inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(11), one O(12), one O(2), and two equivalent O(9) atoms to form distorted WO6 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 W(4)O6 octahedra, and corners with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-35°. The W(1)-O(1) bond length is 1.91 Å. The W(1)-O(11) bond length is 1.87 Å. The W(1)-O(12) bond length is 1.96 Å. The W(1)-O(2) bond length is 1.88 Å. There is one shorter (1.78 Å) and one longer (2.15 Å) W(1)-O(9) bond length. In the second W site, W(2) is bonded to one O(13), one O(14), one O(3), one O(4), and two equivalent O(10) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(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 0-32°. The W(2)-O(13) bond length is 1.92 Å. The W(2)-O(14) bond length is 1.93 Å. The W(2)-O(3) bond length is 1.88 Å. The W(2)-O(4) bond length is 1.89 Å. There is one shorter (1.77 Å) and one longer (2.16 Å) W(2)-O(10) bond length. In the third W site, W(3) is bonded to one O(23), one O(24), one O(25), one O(26), and two equivalent O(27) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 4-33°. The W(3)-O(23) bond length is 1.84 Å. The W(3)-O(24) bond length is 1.95 Å. The W(3)-O(25) bond length is 1.90 Å. The W(3)-O(26) bond length is 1.94 Å. There is one shorter (1.77 Å) and one longer (2.16 Å) W(3)-O(27) bond length. In the fourth W site, W(4) is bonded to one O(12), one O(17), one O(22), one O(24), and two equivalent O(6) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 1-36°. The W(4)-O(12) bond length is 1.89 Å. The W(4)-O(17) bond length is 1.90 Å. The W(4)-O(22) bond length is 1.94 Å. The W(4)-O(24) bond length is 1.90 Å. There is one shorter (1.77 Å) and one longer (2.16 Å) W(4)-O(6) bond length. In the fifth W site, W(5) is bonded to one O(13), one O(20), one O(21), one O(25), and two equivalent O(7) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(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 5-33°. The W(5)-O(13) bond length is 1.94 Å. The W(5)-O(20) bond length is 1.87 Å. The W(5)-O(21) bond length is 1.87 Å. The W(5)-O(25) bond length is 1.96 Å. There is one shorter (1.77 Å) and one longer (2.16 Å) W(5)-O(7) bond length. In the sixth W site, W(6) is bonded to one O(14), one O(19), one O(22), one O(26), and two equivalent O(8) atoms to form distorted WO6 octahedra that share  a cornercorner with one Ta(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 1-33°. The W(6)-O(14) bond length is 1.92 Å. The W(6)-O(19) bond length is 1.89 Å. The W(6)-O(22) bond length is 1.91 Å. The W(6)-O(26) bond length is 1.89 Å. There is one shorter (1.77 Å) and one longer (2.16 Å) W(6)-O(8) bond length. There are twenty-seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one W(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(2), and one W(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(2), and one W(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ta(3) atoms. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent W(4) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent W(5) atoms. In the eighth O site, O(8) is bonded in a linear geometry to two equivalent W(6) atoms. In the ninth O site, O(9) is bonded in a distorted linear geometry to one K(1) and two equivalent W(1) atoms. In the tenth O site, O(10) is bonded in a distorted linear geometry to two equivalent W(2) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(3), and one W(1) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one W(1) and one W(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent K(2), one W(2), and one W(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one W(2) and one W(6) atom. In the fifteenth O site, O(15) is bonded in a linear geometry to one K(1) and two equivalent Ta(1) atoms. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one K(2) and two equivalent Ta(2) atoms. In the seventeenth O site, O(17) is bonded in a 3-coordinate geometry to one K(3), one Ta(1), and one W(4) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(2), and one Ta(3) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(2), and one W(6) atom. In the twentieth O site, O(20) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(1), and one W(5) atom. In the twenty-first O site, O(21) is bonded in a distorted bent 150 degrees geometry to one K(3), one Ta(3), and one W(5) atom. In the twenty-second O site, O(22) is bonded in a distorted bent 150 degrees geometry to one K(3), one W(4), and one W(6) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Ta(3) and one W(3) atom. In the twenty-fourth O site, O(24) is bonded in a bent 150 degrees geometry to one W(3) and one W(4) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to one W(3) and one W(5) atom. In the twenty-sixth O site, O(26) is bonded in a bent 150 degrees geometry to one W(3) and one W(6) atom. In the twenty-seventh O site, O(27) is bonded in a linear geometry to two equivalent W(3) atoms.