KTiPSe5 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), two equivalent Se(3), and four equivalent Se(4) atoms. Ti(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form TiSe6 octahedra that share edges with two equivalent Ti(1)Se6 octahedra and edges with two equivalent P(1)Se4 tetrahedra. P(1) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form PSe4 tetrahedra that share edges with two equivalent Ti(1)Se6 octahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one K(1), two equivalent Ti(1), and one P(1) atom to form distorted SeKTi2P trigonal pyramids that share corners with three equivalent Se(4)K4P square pyramids,  an edgeedge with one Se(4)K4P square pyramid, and  an edgeedge with one Se(1)KTi2P trigonal pyramid. In the second Se site, Se(2) is bonded in an L-shaped geometry to one K(1) and two equivalent Ti(1) atoms. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one K(1), one Ti(1), and one P(1) atom. In the fourth Se site, Se(4) is bonded to four equivalent K(1) and one P(1) atom to form distorted SeK4P square pyramids that share corners with four equivalent Se(4)K4P square pyramids, corners with three equivalent Se(1)KTi2P trigonal pyramids, edges with four equivalent Se(4)K4P square pyramids, and  an edgeedge with one Se(1)KTi2P trigonal pyramid.
KTiPSe5 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), two equivalent Se(3), and four equivalent Se(4) atoms. The K(1)-Se(1) bond length is 3.66 Å. The K(1)-Se(2) bond length is 3.89 Å. Both K(1)-Se(3) bond lengths are 3.46 Å. There are a spread of K(1)-Se(4) bond distances ranging from 3.37-3.74 Å. Ti(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form TiSe6 octahedra that share edges with two equivalent Ti(1)Se6 octahedra and edges with two equivalent P(1)Se4 tetrahedra. Both Ti(1)-Se(1) bond lengths are 2.75 Å. Both Ti(1)-Se(2) bond lengths are 2.43 Å. Both Ti(1)-Se(3) bond lengths are 2.57 Å. P(1) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form PSe4 tetrahedra that share edges with two equivalent Ti(1)Se6 octahedra. The P(1)-Se(1) bond length is 2.24 Å. The P(1)-Se(4) bond length is 2.15 Å. Both P(1)-Se(3) bond lengths are 2.21 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one K(1), two equivalent Ti(1), and one P(1) atom to form distorted SeKTi2P trigonal pyramids that share corners with three equivalent Se(4)K4P square pyramids,  an edgeedge with one Se(4)K4P square pyramid, and  an edgeedge with one Se(1)KTi2P trigonal pyramid. In the second Se site, Se(2) is bonded in an L-shaped geometry to one K(1) and two equivalent Ti(1) atoms. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one K(1), one Ti(1), and one P(1) atom. In the fourth Se site, Se(4) is bonded to four equivalent K(1) and one P(1) atom to form distorted SeK4P square pyramids that share corners with four equivalent Se(4)K4P square pyramids, corners with three equivalent Se(1)KTi2P trigonal pyramids, edges with four equivalent Se(4)K4P square pyramids, and  an edgeedge with one Se(1)KTi2P trigonal pyramid.