Bi2 Fe2 O11 Sr2.591 Perez O, Leligny H, Grebille D, Labbe P, Groult D, Raveau B Journal of Physics: Condensed Matter 7 (1995) 10003-10014 X-ray investigation of the incommensurate modulated structure of Bi2+xSr3-xFe2O9+d _cod_database_code 1001709 _database_code_amcsd 0013280 5.488 5.475 31.50899 90 90 90 Fmmm atom x y z occ Bi1 .0221 0 .2028 .5 Sr1 .5 0 .1176 .7955 Sr2 .5 0 0 Fe1 0 0 .0607 O1 .25 .25 .0668 O2 0 0 .1389 O3 0 0 0 O4 .6917 0 .1973