data_global
_chemical_name_mineral 'Sodium alum'
loop_
_publ_author_name
'Cromer D T'
'Kay M I'
'Larson A C'
_journal_name_full 'Acta Crystallographica'
_journal_volume 22 
_journal_year 1967
_journal_page_first 182
_journal_page_last 187
_publ_section_title
;
 Refinement of the alum structures. II. X-ray and neutron diffraction of
 NaAl(SO4)2*12H2O, gamma alum
;
_database_code_amcsd 0009306
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Na Al S2 O20 H24'
_cell_length_a 12.213
_cell_length_b 12.213
_cell_length_c 12.213
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 1821.659
_exptl_crystal_density_diffrn      1.671
_symmetry_space_group_name_H-M 'P a 3'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+z,x,1/2-y'
  'z,1/2-x,1/2+y'
  '1/2-z,1/2+x,y'
  '-z,-x,-y'
  '1/2+y,1/2-z,-x'
  '1/2-y,-z,1/2+x'
  '-y,1/2+z,1/2-x'
  'y,z,x'
  'x,1/2-y,1/2+z'
  '1/2-x,1/2+y,z'
  '1/2+x,y,1/2-z'
  '-x,-y,-z'
  '1/2-z,-x,1/2+y'
  '-z,1/2+x,1/2-y'
  '1/2+z,1/2-x,-y'
  'z,x,y'
  '1/2-y,1/2+z,x'
  '1/2+y,z,1/2-x'
  'y,1/2-z,1/2+x'
  '-y,-z,-x'
  '-x,1/2+y,1/2-z'
  '1/2+x,1/2-y,-z'
  '1/2-x,-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Na   0.50000   0.50000   0.50000 ?
Al   0.00000   0.00000   0.00000 ?
S   0.26520   0.26520   0.26520 ?
OSl   0.33430   0.33430   0.33430 ?
OS2   0.29570   0.27830   0.15080 ?
Ow3   0.07670   0.04030   0.31880 ?
Ow4   0.13710   0.95960   0.05730 ?
H1   0.58500   0.31900   0.37800   0.04306
H2   0.48600   0.30800   0.38300   0.05066
H3   0.55500   0.20200   0.50200   0.04053
H4   0.58800   0.33900   0.11300   0.03040
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
Na 0.03113 0.03113 0.03113 -0.00227 -0.00227 -0.00227
Al 0.02146 0.02146 0.02146 0.00378 0.00378 0.00378
S 0.03000 0.03000 0.03000 0.00332 0.00332 0.00332
OSl 0.05191 0.05191 0.05191 -0.02199 -0.02199 -0.02199
OS2 0.10707 0.05471 0.04043 -0.07458 0.05539 -0.01269
Ow3 0.04677 0.04466 0.03166 -0.02773 0.00363 0.00831
Ow4 0.02554 0.03310 0.03763 0.00582 -0.00733 0.01307