Brownmillerite Vanpeteghem C B, Angel R J, Zhao J, Ross N L, Redhammer G J, Seifert F Physics and Chemistry of Minerals 35 (2008) 493-504 The effect of oxygen vacancies and aluminium substitution on the high-pressure properties of brownmillerite-structured Ca2Fe2-xAlxO5 Locality: synthetic Note: x = 0.55 Note: P = 7.73 GPa _database_code_amcsd 0017776 5.2866 14.3321 5.5163 90 90 90 I2mb atom x y z occ Biso Ca .495 .10827 .0258 .71 FeM 0 0 0 .87 .56 AlM 0 0 0 .13 .56 FeT .958 .250 .9312 .58 .58 AlT .958 .250 .9312 .42 .58 O1 .258 .9844 .253 .67 O2 .037 .1425 .072 .8 O3 .613 .250 .871 .6