Materials Data on K2Na4Fe2O5 by Materials Project

Abstract

K2Na4Fe2O5 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. K1+ is bonded in a 1-coordinate geometry to five O2- atoms. There are one shorter (2.86 Å) and four longer (3.10 Å) K–O bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.26–2.75 Å. In the second Na1+ site, Na1+ is bonded to four equivalent O2- atoms to form distorted corner-sharing NaO4 trigonal pyramids. All Na–O bond lengths are 2.50 Å. Fe2+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.87 Å) and one longer (1.91 Å) Fe–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted octahedral geometry to two equivalent K1+, two equivalent Na1+, and two equivalent Fe2+ atoms. In the second O2- site, O2- is bonded in a 7-coordinate geometry to two equivalent K1+, four Na1+, and one Fe2+ atom.