data_global
_chemical_name_mineral 'Tugtupite'
loop_
_publ_author_name
'Hassan I'
'Grundy H D'
_journal_name_full 'The Canadian Mineralogist'
_journal_volume 29 
_journal_year 1991
_journal_page_first 385
_journal_page_last 390
_publ_section_title
;
 The crystal structure and thermal expansion of tugtupite,
 Na8[Al2Be2Si8O24]Cl2
;
_database_code_amcsd 0005268
_chemical_formula_sum 'Al Be Si4 O12 Na4 Cl'
_cell_length_a 8.640
_cell_length_b 8.640
_cell_length_c 8.873
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 662.366
_exptl_crystal_density_diffrn      2.345
_symmetry_space_group_name_H-M 'I -4'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Al   0.00000   0.50000   0.75000
Be   0.00000   0.50000   0.25000
Si   0.01270   0.25330   0.49580
O1   0.15040   0.13430   0.44170
O2   0.34720   0.03850   0.64880
O3   0.42560   0.14860   0.13770
Na   0.15630   0.19720   0.18180
Cl   0.00000   0.00000   0.00000
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
Al 0.00780 0.00780 0.00740 0.00000 0.00000 0.00000
Be 0.00860 0.00860 0.01230 0.00000 0.00000 0.00000
Si 0.00710 0.00630 0.00860 -0.00020 -0.00020 -0.00030
O1 0.01260 0.01160 0.01280 0.00460 0.00100 0.00010
O2 0.01070 0.01190 0.01320 -0.00030 -0.00350 -0.00040
O3 0.01120 0.01140 0.01350 -0.00010 0.00050 0.00380
Na 0.02060 0.01600 0.01990 0.00070 0.00240 0.00120
Cl 0.02280 0.02280 0.02440 0.00000 0.00000 0.00000