Ta3CrSe6 is Ilmenite-like structured and crystallizes in the hexagonal P6_322 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent Se(1) atoms to form distorted TaSe6 pentagonal pyramids that share corners with six equivalent Cr(1)Se6 octahedra and edges with six equivalent Ta(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 46°. In the second Ta site, Ta(2) is bonded to six equivalent Se(1) atoms to form distorted TaSe6 pentagonal pyramids that share corners with three equivalent Cr(1)Se6 octahedra, edges with three equivalent Ta(1)Se6 pentagonal pyramids, edges with three equivalent Ta(2)Se6 pentagonal pyramids, and  a faceface with one Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 46°. Cr(1) is bonded to six equivalent Se(1) atoms to form CrSe6 octahedra that share corners with six equivalent Ta(1)Se6 pentagonal pyramids, corners with six equivalent Ta(2)Se6 pentagonal pyramids, and faces with two equivalent Ta(2)Se6 pentagonal pyramids. Se(1) is bonded to one Ta(1), two equivalent Ta(2), and one Cr(1) atom to form a mixture of edge, corner, and face-sharing SeTa3Cr trigonal pyramids.
Ta3CrSe6 is Ilmenite-like structured and crystallizes in the hexagonal P6_322 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent Se(1) atoms to form distorted TaSe6 pentagonal pyramids that share corners with six equivalent Cr(1)Se6 octahedra and edges with six equivalent Ta(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 46°. All Ta(1)-Se(1) bond lengths are 2.60 Å. In the second Ta site, Ta(2) is bonded to six equivalent Se(1) atoms to form distorted TaSe6 pentagonal pyramids that share corners with three equivalent Cr(1)Se6 octahedra, edges with three equivalent Ta(1)Se6 pentagonal pyramids, edges with three equivalent Ta(2)Se6 pentagonal pyramids, and  a faceface with one Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are three shorter (2.59 Å) and three longer (2.63 Å) Ta(2)-Se(1) bond lengths. Cr(1) is bonded to six equivalent Se(1) atoms to form CrSe6 octahedra that share corners with six equivalent Ta(1)Se6 pentagonal pyramids, corners with six equivalent Ta(2)Se6 pentagonal pyramids, and faces with two equivalent Ta(2)Se6 pentagonal pyramids. All Cr(1)-Se(1) bond lengths are 2.57 Å. Se(1) is bonded to one Ta(1), two equivalent Ta(2), and one Cr(1) atom to form a mixture of edge, corner, and face-sharing SeTa3Cr trigonal pyramids.