data_9003349
_chemical_name '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
;
_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
_symmetry_space_group_name_H-M 'I 2 m b'
loop_
_symmetry_equiv_pos_as_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_Uiso_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