data_global
_chemical_name_mineral 'Heulandite-Ca'
loop_
_publ_author_name
'Gunter M E'
'Armbruster T'
'Kohler T'
'Knowles C R'
_journal_name_full 'American Mineralogist'
_journal_volume 79 
_journal_year 1994
_journal_page_first 675
_journal_page_last 682
_publ_section_title
;
 Crystal structure and optical properties of Na- and Pb-exchanged
 heulandite-group zeolites
 Sample: nonexchanged
 Atomic parameters from ICSD
;
_chemical_formula_sum 'Na.65 Ca1.848 K.06 (Si13.554 Al4.446) O48.38 H12.38'
_cell_length_a 17.671
_cell_length_b 17.875
_cell_length_c 7.412
_cell_angle_alpha 90
_cell_angle_beta 116.39
_cell_angle_gamma 90
_cell_volume 2097.242
_exptl_crystal_density_diffrn      2.183
_symmetry_space_group_name_H-M 'C 1 2/m 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,z'
  '1/2+x,1/2-y,z'
  '-x,y,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
  '1/2-x,1/2-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
Na1   0.15490   0.00000   0.66660   0.22800   0.07979
Ca1   0.15490   0.00000   0.66660   0.44000   0.07979
Ca2   0.54020   0.00000   0.20310   0.48400   0.03470
K   0.27630   0.00000   0.01000   0.03000   0.12538
Na2   0.27630   0.00000   0.01000   0.09700   0.12538
Si1   0.17940   0.16980   0.09670   0.75300   0.01697
Al1   0.17940   0.16980   0.09670   0.24700   0.01697
Si2   0.28860   0.08990   0.50080   0.75300   0.01798
Al2   0.28860   0.08990   0.50080   0.24700   0.01798
Si3   0.29170   0.30960   0.28310   0.75300   0.01710
Al3   0.29170   0.30960   0.28310   0.24700   0.01710
Si4   0.06460   0.29840   0.41100   0.75300   0.01697
Al4   0.06460   0.29840   0.41100   0.24700   0.01697
Si5   0.00000   0.21310   0.00000   0.75300   0.01773
Al5   0.00000   0.21310   0.00000   0.24700   0.01773
O1   0.30480   0.00000   0.54660   1.00000   0.03546
O2   0.23130   0.11940   0.61320   1.00000   0.03863
O3   0.18330   0.15430   0.88420   1.00000   0.04078
O4   0.23850   0.10650   0.25550   1.00000   0.03103
O5   0.00000   0.32590   0.50000   1.00000   0.04306
O6   0.08200   0.15870   0.06260   1.00000   0.02812
O7   0.37290   0.26600   0.45080   1.00000   0.04129
O8   0.00890   0.26620   0.18420   1.00000   0.03521
O9   0.21030   0.25420   0.17830   1.00000   0.03344
O10   0.11550   0.37230   0.39880   1.00000   0.03344
O-H11   0.27630   0.00000   0.01000   0.83000   0.12538
O-H12   0.50000   0.00000   0.50000   1.00000   0.10005
O-H13   0.42280   0.08170   0.03070   1.00000   0.06839
O-H14   0.09400   0.00000   0.28500   1.00000   0.16718
O-H15   0.08200   0.00500   0.86700   0.43000   0.14996
O-H16   0.00000   0.08730   0.50000   1.00000   0.25964