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