data_global _chemical_name_mineral 'Tugtupite' loop_ _publ_author_name 'Antao S M' 'Hassan I' 'Parise J B' _journal_name_full 'American Mineralogist' _journal_volume 89 _journal_year 2004 _journal_page_first 492 _journal_page_last 497 _publ_section_title ; Tugtupite: High-temperature structures obtained from in situ synchrotron diffraction and Rietveld refinements T = 644 C ; _database_code_amcsd 0003459 _chemical_formula_sum 'Al Be Si4 O12 Na4 Cl' _cell_length_a 8.67908 _cell_length_b 8.67908 _cell_length_c 8.8950 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 670.029 _exptl_crystal_density_diffrn 2.318 _symmetry_space_group_name_H-M 'I -4' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'y,-x,-z' '1/2+y,1/2-x,1/2-z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' '-y,x,-z' '1/2-y,1/2+x,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Al 0.00000 0.50000 0.75000 0.01820 Be 0.00000 0.50000 0.25000 0.01400 Si 0.01210 0.25440 0.49450 0.01820 O1 0.15010 0.13860 0.44730 0.02190 O2 0.34270 0.03240 0.65210 0.02190 O3 0.43160 0.14450 0.13970 0.02190 Na 0.16120 0.19750 0.18300 0.05500 Cl 0.00000 0.00000 0.00000 0.06810