data_global _chemical_name_mineral 'Koenenite' loop_ _publ_author_name 'Allmann R' 'Lohse H N' 'Hellner E' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 126 _journal_year 1968 _journal_page_first 7 _journal_page_last 22 _publ_section_title ; Die kristallstruktur des koenenits, eine doppelschichtstruktur mit zwei inkommensurablen teilgittern Note: one of two substructures in koenenite ; _database_code_amcsd 0010654 _chemical_formula_sum '(Mg.636 Al.364) (O2 H2)' _cell_length_a 3.052 _cell_length_b 3.052 _cell_length_c 10.880 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 87.766 _exptl_crystal_density_diffrn 1.122 _symmetry_space_group_name_H-M 'P -3 m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-y,-x,z' 'y,-x+y,-z' '-x,-x+y,-z' '-x+y,-x,z' '-x+y,y,z' '-x,-y,-z' 'y,x,-z' '-y,x-y,z' 'x,x-y,z' 'x-y,x,-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 Mg 0.00000 0.00000 0.50000 0.63640 0.01267 Al 0.00000 0.00000 0.50000 0.36360 0.01267 O-H 0.66667 0.33333 0.40860 1.00000 0.02280