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 = 821 C ; _database_code_amcsd 0003462 _chemical_formula_sum 'Al Be Si4 O12 Na4 Cl' _cell_length_a 8.69872 _cell_length_b 8.69872 _cell_length_c 8.9107 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 674.253 _exptl_crystal_density_diffrn 2.304 _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 0.02000 Be 0.00000 0.50000 0.25000 0.01300 Si 0.01180 0.25410 0.49490 0.02000 O1 0.14960 0.13850 0.44970 0.02560 O2 0.34350 0.03210 0.65260 0.02560 O3 0.43440 0.14590 0.14000 0.02560 Na 0.16260 0.19830 0.18320 0.06340 Cl 0.00000 0.00000 0.00000 0.08340