data_global
_chemical_name_mineral 'Brownmillerite'
loop_
_publ_author_name
'Vanpeteghem C B'
'Angel R J'
'Zhao J'
'Ross N L'
'Redhammer G J'
'Seifert F'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 35 
_journal_year 2008
_journal_page_first 493
_journal_page_last 504
_publ_section_title
;
 The effect of oxygen vacancies and aluminium substitution on the
 high-pressure properties of brownmillerite-structured Ca2Fe2-xAlxO5
 Note: x = 0.55
 Note: P = 6.27 GPa
;
_database_code_amcsd 0017775
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Ca2 (Fe1.45 Al.55) O5'
_cell_length_a 5.303
_cell_length_b 14.3778
_cell_length_c 5.5290
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 421.561
_exptl_crystal_density_diffrn      4.033
_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   0.49200   0.10850   0.02560   1.00000   0.00912
FeM   0.00000   0.00000   0.00000   0.87000   0.00760
AlM   0.00000   0.00000   0.00000   0.13000   0.00760
FeT   0.95200   0.25000   0.93090   0.58000   0.00735
AlT   0.95200   0.25000   0.93090   0.42000   0.00735
O1   0.24700   0.98480   0.25800   1.00000   0.00887
O2   0.02500   0.14300   0.07200   1.00000   0.01140
O3   0.60900   0.25000   0.86900   1.00000   0.01013