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