Materials Data on Fe3CuAs2 by Materials Project
Fe3CuAs2 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 5-coordinate geometry to two equivalent Fe, two equivalent Cu, and five equivalent As atoms. Both Fe–Fe bond lengths are 2.64 Å. Both Fe–Cu bond lengths are 2.64 Å. There are one shorter (2.38 Å) and four longer (2.59 Å) Fe–As bond lengths. In the second Fe site, Fe is bonded to four equivalent Fe, four equivalent Cu, and four equivalent As atoms to form distorted FeFe4Cu4As4 cuboctahedra that share corners with four equivalent FeFe4Cu4As4 cuboctahedra, faces with four equivalent FeFe4Cu4As4 cuboctahedra, and faces with four equivalent CuFe8As4 cuboctahedra. All Fe–Cu bond lengths are 2.58 Å. All Fe–As bond lengths are 2.49 Å. Cu is bonded to eight Fe and four equivalent As atoms to form CuFe8As4 cuboctahedra that share corners with four equivalent CuFe8As4 cuboctahedra, faces with four equivalent FeFe4Cu4As4 cuboctahedra, and faces with four equivalent CuFe8As4 cuboctahedra. All Cu–As bond lengths are 2.49 Å. As is bonded in a 9-coordinate geometry to seven Fe and two equivalent Cu atoms.