data_global _chemical_name_mineral 'Mullite' loop_ _publ_author_name 'Fischer R X' 'Schmucker M' 'Angerer P' 'Schneider H' _journal_name_full 'American Mineralogist' _journal_volume 86 _journal_year 2001 _journal_page_first 1513 _journal_page_last 1518 _publ_section_title ; Crystal structures of Na and K aluminate mullites Sample: Na ; _database_code_amcsd 0002749 _chemical_formula_sum 'Na.335 Al3 O4.665' _cell_length_a 7.6819 _cell_length_b 7.6810 _cell_length_c 2.91842 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 172.200 _exptl_crystal_density_diffrn 3.149 _symmetry_space_group_name_H-M 'P b a m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,-z' '1/2-x,1/2+y,z' '1/2+x,1/2-y,-z' 'x,y,-z' '-x,-y,z' '-x,-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 Na 0.08700 0.56100 0.50000 0.16750 0.01773 Al1 0.00000 0.00000 0.00000 1.00000 0.01001 AlT 0.15100 0.33310 0.50000 0.66750 0.01051 AlT* 0.26910 0.19560 0.50000 0.33250 0.01393 Oab 0.36020 0.42110 0.50000 1.00000 0.01659 Oc* 0.48430 0.04580 0.50000 0.33250 0.01393 Od 0.13180 0.21240 0.00000 1.00000 0.01520