Materials Data on La6Al4Fe9As by Materials Project

Abstract

La6Fe9Al4As crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 1-coordinate geometry to eight Fe, four equivalent Al, and one As atom. There are four shorter (3.09 Å) and four longer (3.23 Å) La–Fe bond lengths. All La–Al bond lengths are 3.28 Å. The La–As bond length is 3.44 Å. In the second La site, La is bonded in a 6-coordinate geometry to one Fe, three equivalent Al, and two equivalent As atoms. The La–Fe bond length is 3.18 Å. There are two shorter (3.32 Å) and one longer (3.40 Å) La–Al bond lengths. Both La–As bond lengths are 3.37 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent La, eight Fe, and two equivalent Al atoms to form a mixture of face and corner-sharing FeLa2Al2Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.42–2.56 Å. Both Fe–Al bond lengths are 2.61 Å. In the second Fe site, Fe is bonded to eight Fe and four equivalent Al atoms to form a mixture of face and corner-sharing FeAl4Fe8 cuboctahedra. All Fe–Fe bond lengths are 2.43 Å. All Fe–Al bond lengths are 2.57 Å. In the third Fe site, Fe is bonded in a 12-coordinate geometry to three La, six Fe, and three equivalent Al atoms. The Fe–Fe bond length is 2.65 Å. There are one shorter (2.52 Å) and two longer (2.59 Å) Fe–Al bond lengths. Al is bonded in a 12-coordinate geometry to five La, six Fe, and one Al atom. The Al–Al bond length is 2.73 Å. As is bonded in a distorted q6 geometry to ten La atoms.