Materials Data on LuFeCuO4 by Materials Project
LuFeCuO4 crystallizes in the trigonal R3m space group. The structure is three-dimensional. Lu3+ is bonded to six O2- atoms to form distorted LuO6 octahedra that share corners with three equivalent FeO5 trigonal bipyramids, corners with three equivalent CuO5 trigonal bipyramids, and edges with six equivalent LuO6 octahedra. There are three shorter (2.20 Å) and three longer (2.30 Å) Lu–O bond lengths. Fe3+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent LuO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent CuO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. There are a spread of Fe–O bond distances ranging from 1.94–2.03 Å. Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with three equivalent LuO6 octahedra, corners with six equivalent CuO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 67°. There are a spread of Cu–O bond distances ranging from 1.95–2.08 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Lu3+ and one Cu2+ atom to form OLu3Cu tetrahedra that share corners with nine OLu3Cu tetrahedra, corners with four OFe3Cu trigonal pyramids, and edges with three equivalent OLu3Fe tetrahedra. In the second O2- site, O2- is bonded to three equivalent Lu3+ and one Fe3+ atom to form distorted OLu3Fe tetrahedra that share corners with nine OLu3Cu tetrahedra, corners with four OFe3Cu trigonal pyramids, and edges with three equivalent OLu3Cu tetrahedra. In the third O2- site, O2- is bonded to three equivalent Fe3+ and one Cu2+ atom to form OFe3Cu trigonal pyramids that share corners with four OLu3Cu tetrahedra, corners with six equivalent OFe3Cu trigonal pyramids, and edges with three equivalent OFeCu3 trigonal pyramids. In the fourth O2- site, O2- is bonded to one Fe3+ and three equivalent Cu2+ atoms to form OFeCu3 trigonal pyramids that share corners with four OLu3Cu tetrahedra, corners with six equivalent OFeCu3 trigonal pyramids, and edges with three equivalent OFe3Cu trigonal pyramids.