data_global _chemical_name_mineral 'Leonite' loop_ _publ_author_name 'Hertweck B' 'Giester G' 'Libowitzky E' _journal_name_full 'American Mineralogist' _journal_volume 86 _journal_year 2001 _journal_page_first 1282 _journal_page_last 1292 _publ_section_title ; The crystal structures of the low-temperature phases of leonite-type compounds, K2Me(SO4)2.4H2O (Me=Mg,Mn,Fe) Sample: K2Mg(SO4)2.4H2O, T = 100 K ; _database_code_amcsd 0002727 _chemical_formula_sum 'K2 Mg S2 O12 H8' _cell_length_a 11.778 _cell_length_b 9.469 _cell_length_c 9.851 _cell_angle_alpha 90 _cell_angle_beta 95.26 _cell_angle_gamma 90 _cell_volume 1094.015 _exptl_crystal_density_diffrn 2.226 _symmetry_space_group_name_H-M 'P 1 21/a 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-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 0.16666 0.26914 0.23925 0.00850 K2 0.16772 -0.25681 0.25944 0.00810 Mg1 0.00000 0.00000 0.00000 0.00570 Mg2 0.00000 0.50000 0.50000 0.00530 S1 0.20787 0.50544 -0.04393 0.00500 S2 0.21302 -0.00636 -0.48126 0.00480 O1A -0.15500 0.37040 0.11720 0.00870 O1B 0.16270 0.37400 -0.11160 0.00940 O2A 0.14950 0.09190 -0.39930 0.00880 O2B 0.18030 -0.15320 -0.45470 0.00970 O3 0.16850 0.01140 0.05550 0.01160 O4 0.18270 0.50790 0.09810 0.01150 O5 0.16360 0.51100 0.43770 0.00750 O6 0.19010 0.02370 0.37230 0.00990 Ow1A -0.03530 0.33980 0.35980 0.00790 Ow1B 0.04510 0.34240 -0.35830 0.00810 Ow2 -0.00530 0.21900 -0.01180 0.01130 Ow3 0.01530 -0.01030 -0.20960 0.01120 H1A -0.07500 0.27600 0.39500 0.02200 H2A -0.07700 0.35500 0.28200 0.03200 H1B 0.07600 0.26900 -0.38700 0.02000 H2B 0.08300 0.35900 -0.28100 0.03800 H3A -0.05200 0.27000 0.02300 0.03000 H3B 0.04500 0.27000 -0.03600 0.03300 H4 0.06800 0.00800 -0.25700 0.02100 H5 -0.04200 -0.01200 -0.26500 0.01900