K3TiO4F3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(1), two equivalent O(2), one F(1), and two equivalent F(2) atoms to form distorted KO4F3 pentagonal bipyramids that share corners with five equivalent Ti(1)O4F3 pentagonal bipyramids, corners with two equivalent O(2)K3TiO trigonal bipyramids, and  an edgeedge with one Ti(1)O4F3 pentagonal bipyramid. In the second K site, K(2) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), one F(1), and two equivalent F(2) atoms to form distorted TiO4F3 pentagonal bipyramids that share corners with five equivalent K(1)O4F3 pentagonal bipyramids, corners with two equivalent O(2)K3TiO trigonal bipyramids, and  an edgeedge with one K(1)O4F3 pentagonal bipyramid. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one K(1), four equivalent K(2), one Ti(1), and one O(2) atom. In the second O site, O(2) is bonded to one K(1), two equivalent K(2), one Ti(1), and one O(1) atom to form distorted OK3TiO trigonal bipyramids that share corners with four equivalent F(1)K5Ti octahedra,  a cornercorner with one K(1)O4F3 pentagonal bipyramid,  a cornercorner with one Ti(1)O4F3 pentagonal bipyramid, corners with two equivalent O(2)K3TiO trigonal bipyramids,  an edgeedge with one F(1)K5Ti octahedra, and  an edgeedge with one O(2)K3TiO trigonal bipyramid. The corner-sharing octahedral tilt angles range from 19-45°. There are two inequivalent F sites. In the first F site, F(1) is bonded to one K(1), four equivalent K(2), and one Ti(1) atom to form distorted FK5Ti octahedra that share corners with eight equivalent O(2)K3TiO trigonal bipyramids, edges with two equivalent F(1)K5Ti octahedra, and edges with two equivalent O(2)K3TiO trigonal bipyramids. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one Ti(1) atom.
K3TiO4F3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(1), two equivalent O(2), one F(1), and two equivalent F(2) atoms to form distorted KO4F3 pentagonal bipyramids that share corners with five equivalent Ti(1)O4F3 pentagonal bipyramids, corners with two equivalent O(2)K3TiO trigonal bipyramids, and  an edgeedge with one Ti(1)O4F3 pentagonal bipyramid. Both K(1)-O(1) bond lengths are 2.82 Å. Both K(1)-O(2) bond lengths are 2.73 Å. The K(1)-F(1) bond length is 2.66 Å. Both K(1)-F(2) bond lengths are 2.58 Å. In the second K site, K(2) is bonded in a 10-coordinate geometry to two equivalent O(2), four equivalent O(1), two equivalent F(1), and two equivalent F(2) atoms. Both K(2)-O(2) bond lengths are 2.76 Å. There are two shorter (3.13 Å) and two longer (3.14 Å) K(2)-O(1) bond lengths. Both K(2)-F(1) bond lengths are 2.96 Å. Both K(2)-F(2) bond lengths are 2.79 Å. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), one F(1), and two equivalent F(2) atoms to form distorted TiO4F3 pentagonal bipyramids that share corners with five equivalent K(1)O4F3 pentagonal bipyramids, corners with two equivalent O(2)K3TiO trigonal bipyramids, and  an edgeedge with one K(1)O4F3 pentagonal bipyramid. Both Ti(1)-O(1) bond lengths are 1.99 Å. Both Ti(1)-O(2) bond lengths are 1.93 Å. The Ti(1)-F(1) bond length is 2.01 Å. Both Ti(1)-F(2) bond lengths are 1.97 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one K(1), four equivalent K(2), one Ti(1), and one O(2) atom. The O(1)-O(2) bond length is 1.48 Å. In the second O site, O(2) is bonded to one K(1), two equivalent K(2), one Ti(1), and one O(1) atom to form distorted OK3TiO trigonal bipyramids that share corners with four equivalent F(1)K5Ti octahedra,  a cornercorner with one K(1)O4F3 pentagonal bipyramid,  a cornercorner with one Ti(1)O4F3 pentagonal bipyramid, corners with two equivalent O(2)K3TiO trigonal bipyramids,  an edgeedge with one F(1)K5Ti octahedra, and  an edgeedge with one O(2)K3TiO trigonal bipyramid. The corner-sharing octahedral tilt angles range from 19-45°. There are two inequivalent F sites. In the first F site, F(1) is bonded to one K(1), four equivalent K(2), and one Ti(1) atom to form distorted FK5Ti octahedra that share corners with eight equivalent O(2)K3TiO trigonal bipyramids, edges with two equivalent F(1)K5Ti octahedra, and edges with two equivalent O(2)K3TiO trigonal bipyramids. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one Ti(1) atom.