data_global
_chemical_name_mineral 'Mullite'
loop_
_publ_author_name
'Angel R J'
'McMullan R K'
'Prewitt C T'
_journal_name_full 'American Mineralogist'
_journal_volume 76 
_journal_year 1991
_journal_page_first 332
_journal_page_last 342
_publ_section_title
;
 Substructure and superstructure of mullite by neutron diffraction
 Model 2 X-ray
;
_database_code_amcsd 0001352
_chemical_formula_sum 'Al2.4 Si.6 O4.8'
_cell_length_a 7.5785
_cell_length_b 7.6817
_cell_length_c 2.8864
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 168.034
_exptl_crystal_density_diffrn      3.131
_symmetry_space_group_name_H-M 'P b a m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  'x,y,-z'
  '-x,-y,z'
  '-x,-y,-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
Al   0.00000   0.00000   0.00000   1.00000 ?
SiT1   0.14800   0.34550   0.50000   0.30000   0.00545
AlT2   0.15020   0.33620   0.50000   0.50000   0.00545
AlT*   0.26220   0.20570   0.50000   0.20000 ?
Oab1   0.35910   0.41100   0.50000   0.30000   0.00519
Oab2   0.35090   0.43560   0.50000   0.50000   0.00519
Oab*   0.37910   0.40390   0.50000   0.20000   0.00519
Oc   0.50000   0.00000   0.50000   0.40000 ?
Oc*   0.45010   0.05020   0.50000   0.20000 ?
Od   0.11880   0.22590   0.02400   0.30000   0.00646
Od*   0.14090   0.20670   0.02000   0.20000   0.00646
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
Al 0.00698 0.00508 0.00431 0.00059 0.00000 0.00000
AlT* 0.00233 0.00568 0.00506 -0.00059 0.00000 0.00000
Oc 0.01426 0.01285 0.02659 -0.00177 0.00000 0.00000
Oc* 0.00611 0.00478 0.01224 -0.00088 0.00000 0.00000