Materials Data on Ta2Pd3Se8 by Materials Project
Ta2Pd3Se8 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Ta5+ is bonded to six Se2- atoms to form distorted TaSe6 pentagonal pyramids that share corners with two equivalent PdSe5 square pyramids, edges with two equivalent TaSe6 pentagonal pyramids, and edges with two equivalent PdSe5 square pyramids. There are a spread of Ta–Se bond distances ranging from 2.57–2.65 Å. There are two inequivalent Pd2+ sites. In the first Pd2+ site, Pd2+ is bonded to five Se2- atoms to form PdSe5 square pyramids that share corners with two equivalent TaSe6 pentagonal pyramids, edges with two equivalent TaSe6 pentagonal pyramids, and edges with two equivalent PdSe5 square pyramids. There are four shorter (2.50 Å) and one longer (2.70 Å) Pd–Se bond lengths. In the second Pd2+ site, Pd2+ is bonded in a square co-planar geometry to four Se2- atoms. All Pd–Se bond lengths are 2.47 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Pd2+ atoms. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Pd2+ atoms. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ta5+ and two Pd2+ atoms. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Ta5+ and one Pd2+ atom.