data_global
_chemical_name_mineral 'Gonnardite'
loop_
_publ_author_name
'Artioli G'
'Galli E'
_journal_name_full 'American Mineralogist'
_journal_volume 84 
_journal_year 1999
_journal_page_first 1445
_journal_page_last 1450
_publ_section_title
;
 Gonnardite: Re-examination of holotype material, and discreditation of
 tetranatrolite
;
_database_code_amcsd 0002315
_chemical_formula_sum '(Si2.85 Al2.15) Ca.46 Na1.16 O13.4'
_cell_length_a 13.2670
_cell_length_b 13.2670
_cell_length_c 6.6023
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 1162.093
_exptl_crystal_density_diffrn      2.272
_symmetry_space_group_name_H-M 'I -4 2 d'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/2-y,-x,3/4+z'
  '-y,1/2-x,1/4+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,1/2+y,1/4-z'
  '1/2-x,+y,3/4-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  '1/2+y,x,3/4+z'
  '+y,1/2+x,1/4+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
  'x,1/2-y,1/4-z'
  '1/2+x,-y,3/4-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   0.00000   0.00000   0.00000   0.57000   0.02500
Al1   0.00000   0.00000   0.00000   0.43000   0.02500
Si2   0.13190   0.05120   0.38450   0.57000   0.02900
Al2   0.13190   0.05120   0.38450   0.43000   0.02900
Ca   0.30050   0.25000   0.12500   0.23000   0.01300
Na   0.30050   0.25000   0.12500   0.58000   0.01300
O1   0.25000   0.09490   0.37500   1.00000   0.03100
O2   0.09030   0.44780   0.10100   1.00000   0.02900
O3   0.43730   0.37210   0.02600   1.00000   0.02700
OW1   0.25000   0.36510   0.37500   1.00000   0.04600
OW2   0.13900   0.23500   0.05100   0.35000   0.03700