data_global _chemical_name_mineral 'Leucite' loop_ _publ_author_name 'Palmer D C' 'Dove M T' 'Ibberson R M' 'Powell B M' _journal_name_full 'American Mineralogist' _journal_volume 82 _journal_year 1997 _journal_page_first 16 _journal_page_last 29 _publ_section_title ; Structural behavior, crystal chemistry and phase transitions in substituted leucites: High-resolution neutron powder diffraction studies Sample: Expt. no. 3757, T = 298 K, KFeSi2O6 ; _database_code_amcsd 0001854 _chemical_formula_sum 'K.9 Si2 O6' _cell_length_a 13.20357 _cell_length_b 13.20357 _cell_length_c 13.95446 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 2432.741 _exptl_crystal_density_diffrn 2.046 _symmetry_space_group_name_H-M 'I 41/a' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '3/4+y,1/4-x,1/4-z' '1/4+y,3/4-x,3/4-z' '3/4-y,1/4+x,1/4+z' '1/4-y,3/4+x,3/4+z' '1/2+x,y,1/2-z' '+x,1/2+y,-z' '1/2-x,-y,1/2+z' '-x,1/2-y,+z' '3/4-y,3/4+x,3/4-z' '1/4-y,1/4+x,1/4-z' '3/4+y,3/4-x,3/4+z' '1/4+y,1/4-x,1/4+z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy K 0.36500 0.36240 0.11620 0.90000 Si1 0.05790 0.39640 0.16650 0.66667 Si2 0.16730 0.61230 0.12650 0.66667 Si3 0.39050 0.64440 0.08430 0.66667 O1 0.13100 0.31550 0.10870 1.00000 O2 0.08620 0.51280 0.13290 1.00000 O3 0.14630 0.68280 0.22740 1.00000 O4 0.12820 0.68430 0.03640 1.00000 O5 0.28920 0.57290 0.12340 1.00000 O6 0.48130 0.61830 0.16840 1.00000 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 0.10727 0.02597 0.13526 0.00088 -0.05497 -0.04116 Si1 0.00456 0.02014 0.03964 0.00000 -0.00557 -0.01140 Si2 0.01760 0.03508 0.00342 -0.00735 -0.00887 0.00127 Si3 0.02381 0.02521 0.00772 -0.00697 0.00177 -0.00570 O1 0.08941 0.04167 0.10651 -0.01355 0.01849 0.00279 O2 0.04027 0.07852 0.06776 -0.00709 -0.01520 0.00050 O3 0.05294 0.04079 0.04952 0.01304 0.02685 0.00709 O4 0.03686 0.07649 0.03141 0.00659 0.01317 0.01089 O5 0.04964 0.03103 0.05598 -0.00735 0.00988 -0.01951 O6 0.02267 0.04420 0.06079 0.01988 -0.00735 -0.00646