Hercynite Hill R J American Mineralogist 69 (1984) 937-942 X-ray powder diffraction profile refinement of synthetic hercynite inversion parameter = .163 _database_code_amcsd 0000958 8.15579 8.15579 8.15579 90 90 90 *Fd3m .125 .125 .125 atom x y z Biso Fe .125 .125 .125 .56 Al .5 .5 .5 .44 O .2633 .2633 .2633 1.07