Materials Data on BaLa2Fe2O7 by Materials Project
La2BaFe2O7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. There are four shorter (2.83 Å) and eight longer (2.99 Å) Ba–O bond lengths. La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.32–2.87 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with five equivalent FeO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Fe–O bond distances ranging from 2.01–2.25 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to five equivalent La3+ and one Fe3+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent La3+, and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded to four equivalent Ba2+ and two equivalent Fe3+ atoms to form a mixture of distorted corner and edge-sharing OBa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 0°.