data_global _amcsd_formula_title 'K2CuSi4O10' loop_ _publ_author_name 'Kawamura K' 'Iiyama J T' _journal_name_full 'Bulletin de Mineralogie' _journal_volume 104 _journal_year 1981 _journal_page_first 387 _journal_page_last 395 _publ_section_title ; Crystallochemistry and thermochemistry of sodipotassic copper silicate Na2-2xK2xCuSi4O10 ; _database_code_amcsd 0012073 _chemical_formula_sum 'K2 Cu Si4 O10' _cell_length_a 11.285 _cell_length_b 8.244 _cell_length_c 11.065 _cell_angle_alpha 90 _cell_angle_beta 110.94 _cell_angle_gamma 90 _cell_volume 961.429 _exptl_crystal_density_diffrn 2.861 _symmetry_space_group_name_H-M 'P 1 21/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv K1 0.02810 0.25000 0.02950 0.02039 K2 0.05500 0.25000 0.44320 0.01267 K3 0.45700 0.25000 0.52390 0.01722 K4 0.41390 0.25000 0.91710 0.01532 Cu 0.21200 0.49690 0.28860 0.00760 Si1 0.25080 0.56530 0.01490 0.00684 Si2 0.46430 0.44100 0.22880 0.00735 Si3 0.26080 0.55640 0.59670 0.00671 Si4 0.08960 0.44060 0.74920 0.00735 O1 0.46300 0.25000 0.19240 0.01684 O2 0.27090 0.75000 0.57990 0.01925 O3 0.06590 0.25000 0.71170 0.02090 O4 0.23460 0.75000 0.95910 0.01229 O5 0.40260 0.53170 0.08740 0.00988 O6 0.17270 0.53000 0.10590 0.01355 O7 0.03190 0.46810 0.24830 0.01368 O8 0.39390 0.48500 0.32490 0.01444 O9 0.24770 0.46090 0.46890 0.01267 O10 0.14070 0.52130 0.64200 0.01393 O11 0.38840 0.49810 0.71620 0.01191 O12 0.20660 0.44520 0.88910 0.01127