Materials Data on Ta3SeI7 by Materials Project
Ta3SeI7 crystallizes in the hexagonal P6_3mc space group. The structure is two-dimensional and consists of two Ta3SeI7 sheets oriented in the (0, 0, 1) direction. Ta3+ is bonded to one Se2- and five I1- atoms to form distorted edge-sharing TaSeI5 octahedra. The Ta–Se bond length is 2.55 Å. There are a spread of Ta–I bond distances ranging from 2.75–3.05 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Ta3+ atoms. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a water-like geometry to two equivalent Ta3+ atoms. In the second I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ta3+ atoms. In the third I1- site, I1- is bonded in a 2-coordinate geometry to two equivalent Ta3+ atoms.