data_global _chemical_name_mineral 'Brownmillerite' loop_ _publ_author_name 'Redhammer G J' 'Tippelt G' 'Roth G' 'Amthauer G' _journal_name_full 'American Mineralogist' _journal_volume 89 _journal_year 2004 _journal_page_first 405 _journal_page_last 420 _publ_section_title ; Structural variations in the brownmillerite series Ca2(Fe2-xAlx)O5: Single-crystal X-ray diffraction at 25 deg C and high temperature X-ray powder diffraction (25 C <= T <= 1000 C) Sample: bht100_2 ; _database_code_amcsd 0003438 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Ca2 (Fe1.091 Al.909) O5' _cell_length_a 5.3469 _cell_length_b 14.5149 _cell_length_c 5.5640 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 431.820 _exptl_crystal_density_diffrn 3.778 _symmetry_space_group_name_H-M 'I 2 m b' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,1/2+y,-z' '1/2+x,+y,1/2-z' 'x,1/2-y,z' '1/2+x,-y,1/2+z' 'x,-y,-z' '1/2+x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv Ca 0.49141 0.10855 0.02702 1.00000 0.00690 FeM 0.00060 0.00000 0.00000 0.75800 0.00440 AlM 0.00060 0.00000 0.00000 0.24200 0.00440 FeT 0.95240 0.25000 0.92830 0.33300 0.00360 AlT 0.95240 0.25000 0.92830 0.66700 0.00360 O1 0.24840 0.98650 0.25280 1.00000 0.00680 O2 0.02150 0.14350 0.06860 1.00000 0.00930 O3 0.61510 0.25000 0.86200 1.00000 0.00770