data_global
_chemical_name_mineral 'Offretite'
loop_
_publ_author_name
'Gualtieri A'
'Artioli G'
'Passaglia E'
'Bigi S'
'Viani A'
'Hanson J C'
_journal_name_full 'American Mineralogist'
_journal_volume 83 
_journal_year 1998
_journal_page_first 590
_journal_page_last 606
_publ_section_title
;
 Crystal structure-crystal chemistry relationships in the zeolites erionite
 and offretite
 Sample from Mt. Semiol
;
_database_code_amcsd 0002005
_chemical_formula_sum '(Si12.78 Al5.22) Ca1.4 K Mg O49.52 H27.04'
_cell_length_a 13.293
_cell_length_b 13.293
_cell_length_c 7.608
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1164.252
_exptl_crystal_density_diffrn      2.052
_symmetry_space_group_name_H-M 'P -6 m 2'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,x-y,-z'
  '-x+y,-x,-z'
  '-y,-x,z'
  '-y,x-y,z'
  '-x+y,y,-z'
  'x,y,-z'
  'x,x-y,z'
  '-x+y,-x,z'
  '-y,-x,-z'
  '-y,x-y,-z'
  '-x+y,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  -0.00040   0.23080   0.20670   0.71000   0.02800
Al1  -0.00040   0.23080   0.20670   0.29000   0.02800
Si2   0.09190   0.42100   0.50000   0.71000   0.03000
Al2   0.09190   0.42100   0.50000   0.29000   0.03000
Ca1   0.66667   0.33333   0.35300   0.43000   0.06700
Ca2   0.66667   0.33333   0.24500   0.27000   0.05200
K   0.00000   0.00000   0.50000   1.00000   0.04000
Mg   0.33333   0.66667   0.00000   1.00000   0.02600
O1   0.02670   0.34760   0.31880   1.00000   0.03000
O2   0.09420   0.90560   0.23400   1.00000   0.01600
O3   0.88490   0.11510   0.28070   1.00000   0.02600
O4   0.00930   0.27220   0.00000   1.00000   0.03200
O5   0.22710   0.77290   0.50000   1.00000   0.01000
O6   0.45450   0.54550   0.50000   1.00000   0.05100
Wat1   0.33333   0.66667   0.25870   1.00000   0.04300
Wat2   0.24370   0.75630   0.00000   0.80000   0.04100
Wat3   0.17400   0.49570   0.00000   0.30000   0.06000
Wat4   0.75790   0.24210   0.50000   1.00000   0.05800
Wat5  -0.43570   0.43570   0.17130   0.35000   0.04200
Wat5b  -0.48200   0.48200   0.12310   0.37000   0.04200