Materials Data on KTa(AgSe2)2 by Materials Project

Abstract

KTa(AgSe2)2 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. K1+ is bonded in a distorted pentagonal planar geometry to five Se2- atoms. There are a spread of K–Se bond distances ranging from 3.62–3.87 Å. Ta5+ is bonded to four Se2- atoms to form TaSe4 tetrahedra that share edges with four AgSe4 tetrahedra. There are a spread of Ta–Se bond distances ranging from 2.42–2.49 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to four Se2- atoms to form AgSe4 tetrahedra that share corners with six AgSe4 tetrahedra and edges with two equivalent TaSe4 tetrahedra. There are two shorter (2.64 Å) and two longer (2.67 Å) Ag–Se bond lengths. In the second Ag1+ site, Ag1+ is bonded to four Se2- atoms to form AgSe4 tetrahedra that share corners with four equivalent AgSe4 tetrahedra and edges with two equivalent TaSe4 tetrahedra. There are one shorter (2.65 Å) and three longer (2.66 Å) Ag–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to one K1+, one Ta5+, and three Ag1+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to one K1+, one Ta5+, and two Ag1+ atoms. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Ta5+, and one Ag1+ atom.