Disorder in maghemite.

Grau-Crespo, R., Al-Baitai, A. Y., Saadoune, I., & De Leeuw, N. H. (2010). 
Vacancy ordering and electronic structure of γ-Fe2O3 (maghemite): a theoretical investigation. 
Journal of Physics. Condensed Matter : An Institute of Physics Journal, 22(25), 255401. 
doi:10.1088/0953-8984/22/25/255401

Supercell should be installed. See Supporting materials for details.
