data_global _chemical_name_mineral 'Heulandite-Ca' loop_ _publ_author_name 'Merkle A B' 'Slaughter M' _journal_name_full 'American Mineralogist' _journal_volume 52 _journal_year 1967 _journal_page_first 273 _journal_page_last 276 _publ_section_title ; The crystal structure of heulandite (Ca,Na2)[Al2Si7O18].6H2O ; _database_code_amcsd 0000154 _chemical_formula_sum 'Ca (Si4.398 Al1.602) O16.002 H8.004' _cell_length_a 17.73 _cell_length_b 17.82 _cell_length_c 7.43 _cell_angle_alpha 90 _cell_angle_beta 116.33 _cell_angle_gamma 90 _cell_volume 2103.955 _exptl_crystal_density_diffrn 2.230 _symmetry_space_group_name_H-M 'C 1 m 1' loop_ _space_group_symop_operation_xyz '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 Ca1 0.14700 0.00000 0.81100 1.00000 Ca2 0.43500 0.00000 0.14700 1.00000 Ca3 0.24200 0.50000 0.30000 1.00000 Si1 0.10900 0.16800 0.40500 0.73300 Al1 0.10900 0.16800 0.40500 0.26700 Si2 0.00200 0.09300 0.00000 0.73300 Al2 0.00200 0.09300 0.00000 0.26700 Si3 0.08000 0.18400 0.78200 0.73300 Al3 0.08000 0.18400 0.78200 0.26700 Si4 0.34200 0.30400 0.90900 0.73300 Al4 0.34200 0.30400 0.90900 0.26700 Si5 0.28700 0.21600 0.50000 0.73300 Al5 0.28700 0.21600 0.50000 0.26700 Si6 0.49500 0.19800 0.21600 0.73300 Al6 0.49500 0.19800 0.21600 0.26700 Si7 0.46800 0.17300 0.59300 0.73300 Al7 0.46800 0.17300 0.59300 0.26700 Si8 0.21600 0.30200 0.08600 0.73300 Al8 0.21600 0.30200 0.08600 0.26700 Si9 0.07200 0.41500 0.00000 0.73300 Al9 0.07200 0.41500 0.00000 0.26700 O1 0.98300 0.00000 0.94700 1.00000 O2 0.06100 0.13000 0.90000 1.00000 O3 0.10200 0.14300 0.60500 1.00000 O4 0.04400 0.12200 0.23500 1.00000 O5 0.29200 0.33800 0.01800 1.00000 O6 0.21100 0.16700 0.42800 1.00000 O7 0.14200 0.25600 0.94300 1.00000 O8 0.29500 0.25900 0.67900 1.00000 O9 0.08400 0.24700 0.31400 1.00000 O10 0.27900 0.28300 0.31300 1.00000 O11 0.37000 0.15100 0.55900 1.00000 O12 0.02300 0.40400 0.75300 1.00000 O13 0.08100 0.50000 0.04400 1.00000 O14 0.46300 0.16200 0.36200 1.00000 O15 0.49200 0.26300 0.66300 1.00000 O16 0.40400 0.37600 0.90600 1.00000 O17 0.02000 0.38000 0.11700 1.00000 O18 0.17000 0.38300 0.10900 1.00000 O19 0.40700 0.23300 0.05500 1.00000 Wat1 0.00600 0.00000 0.52800 0.66700 Wat2 0.29400 0.50000 0.03800 0.66700 Wat3 0.29600 0.50000 0.76700 0.66700 Wat4 0.06500 0.50000 0.51800 0.66700 Wat5 0.38600 0.00000 0.77200 0.66700 Wat6 0.20900 0.00000 0.60100 0.66700 Wat7 0.25600 0.13700 0.00500 0.66700 Wat8 0.21100 0.42300 0.50900 0.66700 Wat9 0.36000 0.42400 0.46900 0.66700 Wat10 0.38900 0.00000 0.40400 0.66700 Wat11 0.37900 0.00000 0.29100 0.66700 Wat12 0.20800 0.00000 0.45000 0.66700 Wat13 0.37500 0.00000 0.52000 0.66700 Wat14 0.22200 0.17200 0.10900 0.66700