Materials Data on Ta4GaSe8 by Materials Project
GaTa4Se8 crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ta+3.25+ is bonded to six Se2- atoms to form distorted TaSe6 pentagonal pyramids that share corners with three equivalent GaSe4 tetrahedra and edges with six equivalent TaSe6 pentagonal pyramids. There are three shorter (2.55 Å) and three longer (2.80 Å) Ta–Se bond lengths. Ga3+ is bonded to four equivalent Se2- atoms to form GaSe4 tetrahedra that share corners with twelve equivalent TaSe6 pentagonal pyramids. All Ga–Se bond lengths are 2.47 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Ta+3.25+ atoms. In the second Se2- site, Se2- is bonded to three equivalent Ta+3.25+ and one Ga3+ atom to form a mixture of edge and corner-sharing SeTa3Ga tetrahedra.