data_global
_chemical_name_mineral 'Brownmillerite'
loop_
_publ_author_name
'Colville A A'
'Geller S'
_journal_name_full 'Acta Crystallographica, Section B'
_journal_volume 27 
_journal_year 1971
_journal_page_first 2311
_journal_page_last 2315
_publ_section_title
;
 The crystal structure of brownmillerite, Ca2FeAlO5
 Note: no bond lengths could be reproduced
;
_database_code_amcsd 0009418
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Ca2 (Fe Al) O5'
_cell_length_a 5.584
_cell_length_b 14.60
_cell_length_c 5.374
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 438.123
_exptl_crystal_density_diffrn      3.684
_symmetry_space_group_name_H-M 'I b m 2'
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
Ca   0.02730   0.10870   0.49200   1.00000
Fe1   0.00000   0.00000   0.00000   0.76000
Fe2   0.92830   0.25000   0.95330   0.24000
Al1   0.00000   0.00000   0.00000   0.24000
Al2   0.92830   0.25000   0.95330   0.76000
O1   0.25230   0.98610   0.24910   1.00000
O2   0.06800   0.14390   0.02460   1.00000
O3   0.86070   0.25000   0.61930   1.00000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Ca 0.00711 0.00864 0.01156 0.00041 -0.00030 0.00000
Fe1 0.00237 0.01188 0.00424 0.00000 0.00000 0.00000
Fe2 0.00284 0.00432 0.00366 0.00000 -0.00106 0.00000
Al1 0.00237 0.01188 0.00424 0.00000 0.00000 0.00000
Al2 0.00284 0.00432 0.00366 0.00000 -0.00106 0.00000
O1 0.00427 0.01188 0.01010 -0.00207 -0.00030 -0.00199
O2 0.00869 0.01296 0.01200 0.00248 -0.00243 0.00318
O3 0.00569 0.00864 0.01083 0.00000 -0.00106 0.00000