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 #1 from Fitta
;
_database_code_amcsd 0002006
_chemical_formula_sum '(Si12.6 Al5.4) Ca1.52 K.96 Mg.97 O51.5 H31'
_cell_length_a 13.390
_cell_length_b 13.390
_cell_length_c 7.598
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1179.753
_exptl_crystal_density_diffrn      2.079
_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  -0.00140   0.23210   0.20870   0.70000   0.03900
Al1  -0.00140   0.23210   0.20870   0.30000   0.03900
Si2   0.08840   0.42310   0.50000   0.70000   0.02000
Al2   0.08840   0.42310   0.50000   0.30000   0.02000
Ca1   0.66667   0.33333   0.40210   0.40000   0.04200
Ca2   0.66667   0.33333   0.26640   0.36000   0.04800
K   0.00000   0.00000   0.50000   0.96000   0.05100
Mg   0.33333   0.66667   0.00000   0.97000   0.04300
O1   0.02600   0.34940   0.31600   1.00000   0.02000
O2   0.09620   0.90370   0.25000   1.00000   0.02800
O3   0.87340   0.12650   0.29260   1.00000   0.06600
O4   0.00520   0.26440   0.00000   1.00000   0.02200
O5   0.23310   0.76680   0.50000   1.00000   0.02600
O6   0.46020   0.53970   0.50000   1.00000   0.03700
Wat1   0.33333   0.66667   0.23350   1.00000   0.12000
Wat2   0.24320   0.75680   0.00000   0.81000   0.06300
Wat3   0.13500   0.51040   0.00000   0.26000   0.06000
Wat4   0.76630   0.23370   0.50000   0.85000   0.05600
Wat5  -0.43250   0.43250   0.16820   1.00000   0.06200
Wat6  -0.25390   0.25390   0.00000   0.32000   0.06000