data_global _chemical_name_mineral 'Langbeinite' loop_ _publ_author_name 'Mereiter K' _journal_name_full 'Neues Jahrbuch fur Mineralogie, Monatshefte' _journal_volume 1979 _journal_year 1979 _journal_page_first 182 _journal_page_last 188 _publ_section_title ; Refinement of the crystal structure of langbeinite, K2Mg2(SO4)3 ; _database_code_amcsd 0017885 _chemical_compound_source 'the Harmstorf deposit, Werratal, Hessen, Germany' _chemical_formula_sum 'K2 Mg2 S3 O12' _cell_length_a 9.919 _cell_length_b 9.919 _cell_length_c 9.919 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 975.896 _exptl_crystal_density_diffrn 2.825 _symmetry_space_group_name_H-M 'P 21 3' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-z,-x,1/2+y' '-z,1/2+x,1/2-y' '1/2+z,1/2-x,-y' 'z,x,y' '1/2+y,1/2-z,-x' '1/2-y,-z,1/2+x' '-y,1/2+z,1/2-x' 'y,z,x' '-x,1/2+y,1/2-z' '1/2+x,1/2-y,-z' '1/2-x,-y,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 K1 0.06673 0.06673 0.06673 0.00189 K2 0.29822 0.29822 0.29822 0.00213 Mg1 0.58508 0.58508 0.58508 0.00082 Mg2 0.84902 0.84902 0.84902 0.00084 S 0.62557 0.46596 0.26784 0.00066 O1 0.65193 0.50333 0.40751 0.00196 O2 0.75011 0.48499 0.19096 0.00232 O3 0.57957 0.32559 0.25888 0.00167 O4 0.52354 0.55420 0.20782 0.00203 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 K1 0.00189 0.00189 0.00189 -0.00016 -0.00016 -0.00016 K2 0.00213 0.00213 0.00213 0.00007 0.00007 0.00007 Mg1 0.00082 0.00082 0.00082 -0.00006 -0.00006 -0.00006 Mg2 0.00084 0.00084 0.00084 0.00000 0.00000 0.00000 S 0.00066 0.00063 0.00068 0.00011 0.00006 0.00000 O1 0.00250 0.00219 0.00120 0.00032 -0.00034 -0.00079 O2 0.00172 0.00257 0.00267 0.00023 0.00152 0.00033 O3 0.00191 0.00079 0.00234 -0.00037 -0.00072 0.00009 O4 0.00187 0.00167 0.00253 0.00098 -0.00084 0.00009