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: bht120_6 ; _database_code_amcsd 0003436 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Ca2 (Fe1.211 Al.789) O5' _cell_length_a 5.3569 _cell_length_b 14.5407 _cell_length_c 5.5735 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 434.137 _exptl_crystal_density_diffrn 3.811 _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 0.49115 0.10854 0.02705 1.00000 0.00760 FeM 0.00060 0.00000 0.00000 0.79100 0.00470 AlM 0.00060 0.00000 0.00000 0.20900 0.00470 FeT 0.95280 0.25000 0.92900 0.42000 0.00430 AlT 0.95280 0.25000 0.92900 0.58000 0.00430 O1 0.24940 0.98611 0.25300 1.00000 0.00740 O2 0.02280 0.14334 0.06910 1.00000 0.01010 O3 0.61350 0.25000 0.86400 1.00000 0.00830