(Zn2+/Mg2+)[Fe3+](2)O-4 spinel oxides can be refined as direct/fully inverted (respectively) spinels but considering cationic and anionic vacancies and/or interstitial atoms instead of a partial inversion rate of the A(2+) and B3+ cations. The refinements results of the X-ray diffraction patterns and Mossbauer spectroscopy spectra are discussed and show the veracity of the new structural formalism. (C) 2008 Elsevier Ltd. All rights reserved.