K3Ti8O17 crystallizes in the monoclinic Cm space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(11), two equivalent O(13), two equivalent O(16), and two equivalent O(2) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(11), two equivalent O(12), and two equivalent O(17) atoms. In the third K site, K(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(10) and two equivalent O(9) atoms. There are eight inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(14), one O(16), one O(3), one O(9), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 31°. In the second Ti site, Ti(2) is bonded to one O(10), one O(15), one O(17), one O(4), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 32°. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(5), one O(7), and two equivalent O(15) atoms. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(6), one O(8), and two equivalent O(14) atoms. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(11), one O(14), one O(16), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 1-27°. In the sixth Ti site, Ti(6) is bonded to one O(11), one O(15), one O(17), one O(2), and two equivalent O(5) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 1-26°. In the seventh Ti site, Ti(7) is bonded to one O(12), one O(3), one O(7), one O(9), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 29°. In the eighth Ti site, Ti(8) is bonded to one O(10), one O(13), one O(4), one O(8), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 27°. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to two equivalent K(2), one Ti(3), and one Ti(5) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent K(1), one Ti(4), and one Ti(6) atom. In the third O site, O(3) is bonded to one Ti(1), one Ti(7), and two equivalent Ti(8) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(10)K2Ti2 tetrahedra,  a cornercorner with one O(14)Ti4 trigonal pyramid,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(3)Ti4 trigonal pyramids,  an edgeedge with one O(9)K2Ti2 tetrahedra, edges with two equivalent O(4)Ti4 trigonal pyramids, and edges with two equivalent O(8)Ti4 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ti(2), one Ti(8), and two equivalent Ti(7) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(15)Ti4 trigonal pyramid,  a cornercorner with one O(8)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids,  an edgeedge with one O(10)K2Ti2 tetrahedra, edges with two equivalent O(3)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ti(3) and two equivalent Ti(6) atoms. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(4) and two equivalent Ti(5) atoms. In the seventh O site, O(7) is bonded to one Ti(3), one Ti(7), and two equivalent Ti(2) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(9)K2Ti2 tetrahedra, corners with two equivalent O(10)K2Ti2 tetrahedra,  a cornercorner with one O(3)Ti4 trigonal pyramid, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(15)Ti4 trigonal pyramids, and edges with two equivalent O(4)Ti4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ti(4), one Ti(8), and two equivalent Ti(1) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(8)Ti4 trigonal pyramids, edges with two equivalent O(14)Ti4 trigonal pyramids, and edges with two equivalent O(3)Ti4 trigonal pyramids. In the ninth O site, O(9) is bonded to two equivalent K(3), one Ti(1), and one Ti(7) atom to form OK2Ti2 tetrahedra that share corners with two equivalent O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(14)Ti4 trigonal pyramid,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids, corners with two equivalent O(8)Ti4 trigonal pyramids,  an edgeedge with one O(10)K2Ti2 tetrahedra, and  an edgeedge with one O(3)Ti4 trigonal pyramid. In the tenth O site, O(10) is bonded to two equivalent K(3), one Ti(2), and one Ti(8) atom to form distorted OK2Ti2 tetrahedra that share corners with two equivalent O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(15)Ti4 trigonal pyramid,  a cornercorner with one O(8)Ti4 trigonal pyramid, corners with two equivalent O(3)Ti4 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids,  an edgeedge with one O(9)K2Ti2 tetrahedra, and  an edgeedge with one O(4)Ti4 trigonal pyramid. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent K(1), two equivalent K(2), one Ti(5), and one Ti(6) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(2), one Ti(3), and one Ti(7) atom. In the thirteenth O site, O(13) is bonded in a distorted water-like geometry to two equivalent K(1), one Ti(4), and one Ti(8) atom. In the fourteenth O site, O(14) is bonded to one Ti(1), one Ti(5), and two equivalent Ti(4) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(9)K2Ti2 tetrahedra,  a cornercorner with one O(3)Ti4 trigonal pyramid, corners with two equivalent O(14)Ti4 trigonal pyramids, and edges with two equivalent O(8)Ti4 trigonal pyramids. In the fifteenth O site, O(15) is bonded to one Ti(2), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)K2Ti2 tetrahedra,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(15)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one Ti(1), and one Ti(5) atom. In the seventeenth O site, O(17) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(2), one Ti(2), and one Ti(6) atom.
K3Ti8O17 crystallizes in the monoclinic Cm space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(11), two equivalent O(13), two equivalent O(16), and two equivalent O(2) atoms. Both K(1)-O(11) bond lengths are 2.96 Å. Both K(1)-O(13) bond lengths are 2.92 Å. Both K(1)-O(16) bond lengths are 2.72 Å. Both K(1)-O(2) bond lengths are 2.82 Å. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(11), two equivalent O(12), and two equivalent O(17) atoms. Both K(2)-O(1) bond lengths are 2.88 Å. Both K(2)-O(11) bond lengths are 3.06 Å. Both K(2)-O(12) bond lengths are 2.83 Å. Both K(2)-O(17) bond lengths are 2.70 Å. In the third K site, K(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(10) and two equivalent O(9) atoms. Both K(3)-O(10) bond lengths are 2.65 Å. Both K(3)-O(9) bond lengths are 2.64 Å. There are eight inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(14), one O(16), one O(3), one O(9), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 31°. The Ti(1)-O(14) bond length is 2.13 Å. The Ti(1)-O(16) bond length is 1.76 Å. The Ti(1)-O(3) bond length is 2.23 Å. The Ti(1)-O(9) bond length is 1.89 Å. Both Ti(1)-O(8) bond lengths are 1.97 Å. In the second Ti site, Ti(2) is bonded to one O(10), one O(15), one O(17), one O(4), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 32°. The Ti(2)-O(10) bond length is 1.88 Å. The Ti(2)-O(15) bond length is 2.15 Å. The Ti(2)-O(17) bond length is 1.76 Å. The Ti(2)-O(4) bond length is 2.23 Å. Both Ti(2)-O(7) bond lengths are 1.98 Å. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(5), one O(7), and two equivalent O(15) atoms. The Ti(3)-O(1) bond length is 1.76 Å. The Ti(3)-O(12) bond length is 1.98 Å. The Ti(3)-O(5) bond length is 2.04 Å. The Ti(3)-O(7) bond length is 2.28 Å. Both Ti(3)-O(15) bond lengths are 1.97 Å. In the fourth Ti site, Ti(4) is bonded in a 6-coordinate geometry to one O(13), one O(2), one O(6), one O(8), and two equivalent O(14) atoms. The Ti(4)-O(13) bond length is 2.00 Å. The Ti(4)-O(2) bond length is 1.76 Å. The Ti(4)-O(6) bond length is 2.04 Å. The Ti(4)-O(8) bond length is 2.29 Å. Both Ti(4)-O(14) bond lengths are 1.97 Å. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(11), one O(14), one O(16), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 1-27°. The Ti(5)-O(1) bond length is 1.96 Å. The Ti(5)-O(11) bond length is 1.87 Å. The Ti(5)-O(14) bond length is 2.22 Å. The Ti(5)-O(16) bond length is 2.12 Å. Both Ti(5)-O(6) bond lengths are 1.96 Å. In the sixth Ti site, Ti(6) is bonded to one O(11), one O(15), one O(17), one O(2), and two equivalent O(5) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 1-26°. The Ti(6)-O(11) bond length is 1.86 Å. The Ti(6)-O(15) bond length is 2.21 Å. The Ti(6)-O(17) bond length is 2.06 Å. The Ti(6)-O(2) bond length is 1.98 Å. Both Ti(6)-O(5) bond lengths are 1.95 Å. In the seventh Ti site, Ti(7) is bonded to one O(12), one O(3), one O(7), one O(9), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 29°. The Ti(7)-O(12) bond length is 1.80 Å. The Ti(7)-O(3) bond length is 2.22 Å. The Ti(7)-O(7) bond length is 2.10 Å. The Ti(7)-O(9) bond length is 1.88 Å. Both Ti(7)-O(4) bond lengths are 1.97 Å. In the eighth Ti site, Ti(8) is bonded to one O(10), one O(13), one O(4), one O(8), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 27°. The Ti(8)-O(10) bond length is 1.88 Å. The Ti(8)-O(13) bond length is 1.81 Å. The Ti(8)-O(4) bond length is 2.18 Å. The Ti(8)-O(8) bond length is 2.08 Å. Both Ti(8)-O(3) bond lengths are 1.96 Å. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to two equivalent K(2), one Ti(3), and one Ti(5) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent K(1), one Ti(4), and one Ti(6) atom. In the third O site, O(3) is bonded to one Ti(1), one Ti(7), and two equivalent Ti(8) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(10)K2Ti2 tetrahedra,  a cornercorner with one O(14)Ti4 trigonal pyramid,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(3)Ti4 trigonal pyramids,  an edgeedge with one O(9)K2Ti2 tetrahedra, edges with two equivalent O(4)Ti4 trigonal pyramids, and edges with two equivalent O(8)Ti4 trigonal pyramids. In the fourth O site, O(4) is bonded to one Ti(2), one Ti(8), and two equivalent Ti(7) atoms to form distorted OTi4 trigonal pyramids that share corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(15)Ti4 trigonal pyramid,  a cornercorner with one O(8)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids,  an edgeedge with one O(10)K2Ti2 tetrahedra, edges with two equivalent O(3)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ti(3) and two equivalent Ti(6) atoms. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(4) and two equivalent Ti(5) atoms. In the seventh O site, O(7) is bonded to one Ti(3), one Ti(7), and two equivalent Ti(2) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(9)K2Ti2 tetrahedra, corners with two equivalent O(10)K2Ti2 tetrahedra,  a cornercorner with one O(3)Ti4 trigonal pyramid, corners with two equivalent O(7)Ti4 trigonal pyramids, edges with two equivalent O(15)Ti4 trigonal pyramids, and edges with two equivalent O(4)Ti4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ti(4), one Ti(8), and two equivalent Ti(1) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(8)Ti4 trigonal pyramids, edges with two equivalent O(14)Ti4 trigonal pyramids, and edges with two equivalent O(3)Ti4 trigonal pyramids. In the ninth O site, O(9) is bonded to two equivalent K(3), one Ti(1), and one Ti(7) atom to form OK2Ti2 tetrahedra that share corners with two equivalent O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(14)Ti4 trigonal pyramid,  a cornercorner with one O(7)Ti4 trigonal pyramid, corners with two equivalent O(4)Ti4 trigonal pyramids, corners with two equivalent O(8)Ti4 trigonal pyramids,  an edgeedge with one O(10)K2Ti2 tetrahedra, and  an edgeedge with one O(3)Ti4 trigonal pyramid. In the tenth O site, O(10) is bonded to two equivalent K(3), one Ti(2), and one Ti(8) atom to form distorted OK2Ti2 tetrahedra that share corners with two equivalent O(10)K2Ti2 tetrahedra, corners with two equivalent O(9)K2Ti2 tetrahedra,  a cornercorner with one O(15)Ti4 trigonal pyramid,  a cornercorner with one O(8)Ti4 trigonal pyramid, corners with two equivalent O(3)Ti4 trigonal pyramids, corners with two equivalent O(7)Ti4 trigonal pyramids,  an edgeedge with one O(9)K2Ti2 tetrahedra, and  an edgeedge with one O(4)Ti4 trigonal pyramid. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent K(1), two equivalent K(2), one Ti(5), and one Ti(6) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(2), one Ti(3), and one Ti(7) atom. In the thirteenth O site, O(13) is bonded in a distorted water-like geometry to two equivalent K(1), one Ti(4), and one Ti(8) atom. In the fourteenth O site, O(14) is bonded to one Ti(1), one Ti(5), and two equivalent Ti(4) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(9)K2Ti2 tetrahedra,  a cornercorner with one O(3)Ti4 trigonal pyramid, corners with two equivalent O(14)Ti4 trigonal pyramids, and edges with two equivalent O(8)Ti4 trigonal pyramids. In the fifteenth O site, O(15) is bonded to one Ti(2), one Ti(6), and two equivalent Ti(3) atoms to form distorted OTi4 trigonal pyramids that share  a cornercorner with one O(10)K2Ti2 tetrahedra,  a cornercorner with one O(4)Ti4 trigonal pyramid, corners with two equivalent O(15)Ti4 trigonal pyramids, and edges with two equivalent O(7)Ti4 trigonal pyramids. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one Ti(1), and one Ti(5) atom. In the seventeenth O site, O(17) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(2), one Ti(2), and one Ti(6) atom.