data_global _chemical_name_mineral 'Montmorillonite' loop_ _publ_author_name 'Gournis D' 'Lappas A' 'Karakassides M A' 'Tobbens D' 'Moukarika A' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 35 _journal_year 2008 _journal_page_first 49 _journal_page_last 58 _publ_section_title ; A neutron diffraction study of alkali cation migration in montmorillonites Sample: Li-mont ; _database_code_amcsd 0009126 _chemical_formula_sum 'Si3.9 Al.86 Li.08 Fe.1 Mg.14 O10 H' _cell_length_a 5.175 _cell_length_b 8.896 _cell_length_c 12.45 _cell_angle_alpha 90 _cell_angle_beta 99.69 _cell_angle_gamma 90 _cell_volume 564.981 _exptl_crystal_density_diffrn 1.783 _symmetry_space_group_name_H-M 'C 1 2/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' '-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 Si1 0.14800 0.16300 0.30900 0.97500 Al1 0.14800 0.16300 0.30900 0.02500 Li 0.00000 0.50000 0.00000 0.08000 Al2 0.00000 0.38400 0.50000 0.38000 Fe2 0.00000 0.38400 0.50000 0.05000 Mg2 0.00000 0.38400 0.50000 0.07000 O1 0.21800 0.00000 0.26100 0.50000 O2 0.40600 0.22600 0.26200 1.00000 O3 0.20100 0.21500 0.43700 1.00000 O-H 0.62700 0.00000 0.38700 0.50000