Materials Data on K2AgI3 by Materials Project

Abstract

K2AgI3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to seven I1- atoms to form distorted KI7 pentagonal bipyramids that share corners with three equivalent KI7 pentagonal bipyramids, corners with four equivalent AgI4 tetrahedra, edges with eleven KI7 pentagonal bipyramids, and edges with three equivalent AgI4 tetrahedra. There are a spread of K–I bond distances ranging from 3.52–3.83 Å. In the second K1+ site, K1+ is bonded to seven I1- atoms to form distorted KI7 pentagonal bipyramids that share corners with seven KI7 pentagonal bipyramids, edges with seven KI7 pentagonal bipyramids, edges with four equivalent AgI4 tetrahedra, and faces with two equivalent KI7 pentagonal bipyramids. There are a spread of K–I bond distances ranging from 3.63–3.78 Å. Ag1+ is bonded to four I1- atoms to form AgI4 tetrahedra that share corners with four equivalent KI7 pentagonal bipyramids, corners with two equivalent AgI4 tetrahedra, and edges with seven KI7 pentagonal bipyramids. There are a spread of Ag–I bond distances ranging from 2.86–2.91 Å. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a 6-coordinate geometry to four K1+ and two equivalent Ag1+ atoms. In the second I1- site, I1- is bonded to five K1+ and one Ag1+ atom to form a mixture of distorted face, edge, and corner-sharing IK5Ag octahedra. The corner-sharing octahedra tilt angles range from 23–57°. In the third I1- site, I1- is bonded to five K1+ and one Ag1+ atom to form a mixture of distorted face, edge, and corner-sharing IK5Ag octahedra. The corner-sharing octahedra tilt angles range from 52–57°.