data_global _chemical_name_mineral 'Kalsilite' loop_ _publ_author_name 'Cellai D' 'Bonazzi P' 'Carpenter M A' _journal_name_full 'American Mineralogist' _journal_volume 82 _journal_year 1997 _journal_page_first 276 _journal_page_last 279 _publ_section_title ; Natural kalsilite, KAlSiO4, with P31c symmetry: Crystal structure and twinning ; _database_code_amcsd 0001874 _chemical_formula_sum 'K Al Si O4' _cell_length_a 5.157 _cell_length_b 5.157 _cell_length_c 8.706 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 200.513 _exptl_crystal_density_diffrn 2.620 _symmetry_space_group_name_H-M 'P 3 1 c' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x-y,-y,1/2+z' '-y,x-y,z' 'y,x,1/2+z' '-x+y,-x,z' '-x,-x+y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z K 0.00000 0.00000 0.25000 Al1 0.33333 0.66667 0.05940 Si2 0.33333 0.66667 0.44160 O1 0.61600 0.01100 0.00000 O2 0.33333 0.66667 0.26000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 K 0.01540 0.01540 0.01870 0.00770 0.00000 0.00000 Al1 0.00130 0.00130 0.01120 0.00065 0.00000 0.00000 Si2 0.01040 0.01040 0.00580 0.00520 0.00000 0.00000 O1 0.00900 0.00900 0.03100 0.00300 0.00600 0.00400 O2 0.03600 0.03600 0.00400 0.01800 0.00000 0.00000