K(Ti3Se4)4 crystallizes in the triclinic P-1 space group. K(1) is bonded in a distorted hexagonal planar geometry to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one Se(2), one Se(5), one Se(7), one Se(8), and two equivalent Se(6) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the second Ti site, Ti(2) is bonded to one Se(1), one Se(6), one Se(7), one Se(8), and two equivalent Se(5) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the third Ti site, Ti(3) is bonded to one Se(1), one Se(4), one Se(7), one Se(8), and two equivalent Se(2) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the fourth Ti site, Ti(4) is bonded to one Se(2), one Se(3), one Se(7), one Se(8), and two equivalent Se(1) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the fifth Ti site, Ti(5) is bonded to one Se(3), one Se(6), one Se(7), one Se(8), and two equivalent Se(4) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the sixth Ti site, Ti(6) is bonded to one Se(4), one Se(5), one Se(7), one Se(8), and two equivalent Se(3) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one K(1), one Ti(2), one Ti(3), and two equivalent Ti(4) atoms. In the second Se site, Se(2) is bonded in a distorted rectangular see-saw-like geometry to one Ti(1), one Ti(4), and two equivalent Ti(3) atoms. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Ti(4), one Ti(5), and two equivalent Ti(6) atoms. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one K(1), one Ti(3), one Ti(6), and two equivalent Ti(5) atoms. In the fifth Se site, Se(5) is bonded to one K(1), one Ti(1), one Ti(6), and two equivalent Ti(2) atoms to form distorted SeKTi4 trigonal bipyramids that share corners with two equivalent Se(7)Ti6 pentagonal pyramids,  a cornercorner with one Se(5)KTi4 trigonal bipyramid,  an edgeedge with one Se(7)Ti6 pentagonal pyramid, edges with two equivalent Se(8)Ti6 pentagonal pyramids, and  an edgeedge with one Se(5)KTi4 trigonal bipyramid. In the sixth Se site, Se(6) is bonded in a distorted rectangular see-saw-like geometry to one Ti(2), one Ti(5), and two equivalent Ti(1) atoms. In the seventh Se site, Se(7) is bonded to one Ti(1), one Ti(2), one Ti(3), one Ti(4), one Ti(5), and one Ti(6) atom to form distorted SeTi6 pentagonal pyramids that share corners with two equivalent Se(5)KTi4 trigonal bipyramids,  an edgeedge with one Se(5)KTi4 trigonal bipyramid, and faces with two equivalent Se(8)Ti6 pentagonal pyramids. In the eighth Se site, Se(8) is bonded to one Ti(1), one Ti(2), one Ti(3), one Ti(4), one Ti(5), and one Ti(6) atom to form distorted SeTi6 pentagonal pyramids that share edges with two equivalent Se(5)KTi4 trigonal bipyramids and faces with two equivalent Se(7)Ti6 pentagonal pyramids.
K(Ti3Se4)4 crystallizes in the triclinic P-1 space group. K(1) is bonded in a distorted hexagonal planar geometry to two equivalent Se(1), two equivalent Se(4), and two equivalent Se(5) atoms. Both K(1)-Se(1) bond lengths are 3.41 Å. Both K(1)-Se(4) bond lengths are 3.41 Å. Both K(1)-Se(5) bond lengths are 3.41 Å. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one Se(2), one Se(5), one Se(7), one Se(8), and two equivalent Se(6) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(1)-Se(2) bond length is 2.66 Å. The Ti(1)-Se(5) bond length is 2.56 Å. The Ti(1)-Se(7) bond length is 2.59 Å. The Ti(1)-Se(8) bond length is 2.60 Å. There is one shorter (2.55 Å) and one longer (2.57 Å) Ti(1)-Se(6) bond length. In the second Ti site, Ti(2) is bonded to one Se(1), one Se(6), one Se(7), one Se(8), and two equivalent Se(5) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(2)-Se(1) bond length is 2.66 Å. The Ti(2)-Se(6) bond length is 2.56 Å. The Ti(2)-Se(7) bond length is 2.60 Å. The Ti(2)-Se(8) bond length is 2.60 Å. There is one shorter (2.55 Å) and one longer (2.57 Å) Ti(2)-Se(5) bond length. In the third Ti site, Ti(3) is bonded to one Se(1), one Se(4), one Se(7), one Se(8), and two equivalent Se(2) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(3)-Se(1) bond length is 2.57 Å. The Ti(3)-Se(4) bond length is 2.67 Å. The Ti(3)-Se(7) bond length is 2.60 Å. The Ti(3)-Se(8) bond length is 2.60 Å. Both Ti(3)-Se(2) bond lengths are 2.56 Å. In the fourth Ti site, Ti(4) is bonded to one Se(2), one Se(3), one Se(7), one Se(8), and two equivalent Se(1) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(4)-Se(2) bond length is 2.56 Å. The Ti(4)-Se(3) bond length is 2.65 Å. The Ti(4)-Se(7) bond length is 2.60 Å. The Ti(4)-Se(8) bond length is 2.59 Å. Both Ti(4)-Se(1) bond lengths are 2.56 Å. In the fifth Ti site, Ti(5) is bonded to one Se(3), one Se(6), one Se(7), one Se(8), and two equivalent Se(4) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(5)-Se(3) bond length is 2.56 Å. The Ti(5)-Se(6) bond length is 2.65 Å. The Ti(5)-Se(7) bond length is 2.59 Å. The Ti(5)-Se(8) bond length is 2.60 Å. Both Ti(5)-Se(4) bond lengths are 2.56 Å. In the sixth Ti site, Ti(6) is bonded to one Se(4), one Se(5), one Se(7), one Se(8), and two equivalent Se(3) atoms to form a mixture of corner, face, and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Ti(6)-Se(4) bond length is 2.57 Å. The Ti(6)-Se(5) bond length is 2.67 Å. The Ti(6)-Se(7) bond length is 2.59 Å. The Ti(6)-Se(8) bond length is 2.60 Å. Both Ti(6)-Se(3) bond lengths are 2.56 Å. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one K(1), one Ti(2), one Ti(3), and two equivalent Ti(4) atoms. In the second Se site, Se(2) is bonded in a distorted rectangular see-saw-like geometry to one Ti(1), one Ti(4), and two equivalent Ti(3) atoms. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Ti(4), one Ti(5), and two equivalent Ti(6) atoms. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one K(1), one Ti(3), one Ti(6), and two equivalent Ti(5) atoms. In the fifth Se site, Se(5) is bonded to one K(1), one Ti(1), one Ti(6), and two equivalent Ti(2) atoms to form distorted SeKTi4 trigonal bipyramids that share corners with two equivalent Se(7)Ti6 pentagonal pyramids,  a cornercorner with one Se(5)KTi4 trigonal bipyramid,  an edgeedge with one Se(7)Ti6 pentagonal pyramid, edges with two equivalent Se(8)Ti6 pentagonal pyramids, and  an edgeedge with one Se(5)KTi4 trigonal bipyramid. In the sixth Se site, Se(6) is bonded in a distorted rectangular see-saw-like geometry to one Ti(2), one Ti(5), and two equivalent Ti(1) atoms. In the seventh Se site, Se(7) is bonded to one Ti(1), one Ti(2), one Ti(3), one Ti(4), one Ti(5), and one Ti(6) atom to form distorted SeTi6 pentagonal pyramids that share corners with two equivalent Se(5)KTi4 trigonal bipyramids,  an edgeedge with one Se(5)KTi4 trigonal bipyramid, and faces with two equivalent Se(8)Ti6 pentagonal pyramids. In the eighth Se site, Se(8) is bonded to one Ti(1), one Ti(2), one Ti(3), one Ti(4), one Ti(5), and one Ti(6) atom to form distorted SeTi6 pentagonal pyramids that share edges with two equivalent Se(5)KTi4 trigonal bipyramids and faces with two equivalent Se(7)Ti6 pentagonal pyramids.