Materials Data on Fe7C3 by Materials Project

Abstract

Fe7C3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are five inequivalent Fe sites. In the first Fe site, Fe is bonded in a 3-coordinate geometry to three C atoms. There are a spread of Fe–C bond distances ranging from 1.97–2.04 Å. In the second Fe site, Fe is bonded in a 3-coordinate geometry to three C atoms. There is one shorter (1.93 Å) and two longer (1.98 Å) Fe–C bond length. In the third Fe site, Fe is bonded in a water-like geometry to two equivalent C atoms. Both Fe–C bond lengths are 1.98 Å. In the fourth Fe site, Fe is bonded in a distorted trigonal planar geometry to three C atoms. There is one shorter (1.96 Å) and two longer (1.99 Å) Fe–C bond length. In the fifth Fe site, Fe is bonded in a 4-coordinate geometry to four C atoms. There are a spread of Fe–C bond distances ranging from 2.02–2.44 Å. There are two inequivalent C sites. In the first C site, C is bonded in a 7-coordinate geometry to seven Fe atoms. In the second C site, C is bonded in a 6-coordinate geometry to eight Fe atoms.