Ti(NbSe2)3 is Ilmenite-like structured and crystallizes in the orthorhombic C222_1 space group. 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 corners with six equivalent Nb(1)Se6 pentagonal pyramids, corners with six equivalent Nb(2)Se6 pentagonal pyramids, and faces with two equivalent Nb(2)Se6 pentagonal pyramids. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted NbSe6 pentagonal pyramids that share corners with six equivalent Ti(1)Se6 octahedra and edges with six equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 46°. In the second Nb site, Nb(2) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted NbSe6 pentagonal pyramids that share corners with three equivalent Ti(1)Se6 octahedra, edges with three equivalent Nb(1)Se6 pentagonal pyramids, edges with three equivalent Nb(2)Se6 pentagonal pyramids, and  a faceface with one Ti(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms. In the second Se site, Se(2) is bonded to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms to form a mixture of corner and edge-sharing SeTiNb3 trigonal pyramids. In the third Se site, Se(3) is bonded to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms to form a mixture of face, corner, and edge-sharing SeTiNb3 trigonal pyramids.
Ti(NbSe2)3 is Ilmenite-like structured and crystallizes in the orthorhombic C222_1 space group. 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 corners with six equivalent Nb(1)Se6 pentagonal pyramids, corners with six equivalent Nb(2)Se6 pentagonal pyramids, and faces with two equivalent Nb(2)Se6 pentagonal pyramids. Both Ti(1)-Se(1) bond lengths are 2.59 Å. Both Ti(1)-Se(2) bond lengths are 2.60 Å. Both Ti(1)-Se(3) bond lengths are 2.59 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted NbSe6 pentagonal pyramids that share corners with six equivalent Ti(1)Se6 octahedra and edges with six equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 46°. Both Nb(1)-Se(1) bond lengths are 2.61 Å. Both Nb(1)-Se(2) bond lengths are 2.62 Å. Both Nb(1)-Se(3) bond lengths are 2.62 Å. In the second Nb site, Nb(2) is bonded to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms to form distorted NbSe6 pentagonal pyramids that share corners with three equivalent Ti(1)Se6 octahedra, edges with three equivalent Nb(1)Se6 pentagonal pyramids, edges with three equivalent Nb(2)Se6 pentagonal pyramids, and  a faceface with one Ti(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 46°. There is one shorter (2.62 Å) and one longer (2.63 Å) Nb(2)-Se(1) bond length. There is one shorter (2.62 Å) and one longer (2.64 Å) Nb(2)-Se(2) bond length. There is one shorter (2.61 Å) and one longer (2.64 Å) Nb(2)-Se(3) bond length. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms. In the second Se site, Se(2) is bonded to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms to form a mixture of corner and edge-sharing SeTiNb3 trigonal pyramids. In the third Se site, Se(3) is bonded to one Ti(1), one Nb(1), and two equivalent Nb(2) atoms to form a mixture of face, corner, and edge-sharing SeTiNb3 trigonal pyramids.