data_global
_chemical_name_mineral 'Beryl'
loop_
_publ_author_name
'Aurisicchio C'
'Fioravanti G'
'Grubessi O'
'Zanazzi P F'
_journal_name_full 'American Mineralogist'
_journal_volume 73 
_journal_year 1988
_journal_page_first 826
_journal_page_last 837
_publ_section_title
;
 Reappraisal of the crystal chemistry of beryl
 Sample: 3
;
_database_code_amcsd 0001172
_chemical_compound_source 'Mount Cervandone, Val d'Ossola, Piedmont, Italy'
_chemical_formula_sum 'Si6.111 Be2.859 Li.027 Al1.311 Fe.366 Mg.328 O18 Na.406 Cs.012'
_cell_length_a 9.2736
_cell_length_b 9.2736
_cell_length_c 9.1910
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 684.526
_exptl_crystal_density_diffrn      2.718
_symmetry_space_group_name_H-M 'P 6/m c c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-x+y,1/2+z'
  'x,x-y,1/2-z'
  '-x+y,-x,-z'
  'x-y,x,z'
  '-y,-x,1/2+z'
  'y,x,1/2-z'
  'y,-x+y,-z'
  '-y,x-y,z'
  'x-y,-y,1/2+z'
  '-x+y,y,1/2-z'
  'x,y,-z'
  '-x,-y,z'
  'x,x-y,1/2+z'
  '-x,-x+y,1/2-z'
  'x-y,x,-z'
  '-x+y,-x,z'
  'y,x,1/2+z'
  '-y,-x,1/2-z'
  '-y,x-y,-z'
  'y,-x+y,z'
  '-x+y,y,1/2+z'
  'x-y,-y,1/2-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
Si1   0.38520   0.11220   0.00000   1.00000 ?
Be   0.50000   0.00000   0.25000   0.95300   0.00600
Li   0.50000   0.00000   0.25000   0.00900   0.00600
Si2   0.50000   0.00000   0.25000   0.03700   0.00600
Al1   0.50000   0.00000   0.25000   0.00100   0.00600
Al2   0.66667   0.33333   0.25000   0.65400 ?
Fe1   0.66667   0.33333   0.25000   0.03700 ?
Fe2   0.66667   0.33333   0.25000   0.14600 ?
Mg   0.66667   0.33333   0.25000   0.16400 ?
O1   0.30620   0.23150   0.00000   1.00000 ?
O2   0.49510   0.14180   0.14500   1.00000 ?
Na   0.00000   0.00000   0.25000   0.40600 ?
Cs   0.00000   0.00000   0.25000   0.01200 ?
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
Si1 0.00620 0.00630 0.00160 0.00340 0.00000 0.00000
Al2 0.00840 0.00840 0.00490 0.00420 0.00000 0.00000
Fe1 0.00840 0.00840 0.00490 0.00420 0.00000 0.00000
Fe2 0.00840 0.00840 0.00490 0.00420 0.00000 0.00000
Mg 0.00840 0.00840 0.00490 0.00420 0.00000 0.00000
O1 0.01470 0.01410 0.01470 0.01140 0.00000 0.00000
O2 0.01300 0.01350 0.00450 0.00850 -0.00240 -0.00010
Na 0.05800 0.05800 0.03230 0.02900 0.00000 0.00000
Cs 0.05800 0.05800 0.03230 0.02900 0.00000 0.00000