data_global _chemical_name_mineral 'Archerite' loop_ _publ_author_name 'Nelmes R J' 'Meyer G M' 'Tibballs J E' _journal_name_full 'Journal of Physics C: Solid State Physics' _journal_volume 15 _journal_year 1982 _journal_page_first 59 _journal_page_last 75 _publ_section_title ; The crystal structure of tetragonal KH2PO4 and KD2PO4 as a function of temperature Sample: T = 295 K ; _database_code_amcsd 0013165 _chemical_formula_sum 'K H2 P O4' _cell_length_a 7.4521 _cell_length_b 7.4521 _cell_length_c 6.974 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 387.293 _exptl_crystal_density_diffrn 2.334 _symmetry_space_group_name_H-M 'I -4 2 d' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '1/2-y,-x,3/4+z' '-y,1/2-x,1/4+z' 'y,-x,-z' '1/2+y,1/2-x,1/2-z' '-x,1/2+y,1/4-z' '1/2-x,+y,3/4-z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' '1/2+y,x,3/4+z' '+y,1/2+x,1/4+z' '-y,x,-z' '1/2-y,1/2+x,1/2-z' 'x,1/2-y,1/4-z' '1/2+x,-y,3/4-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy K 0.00000 0.00000 0.50000 1.00000 H 0.14757 0.22559 0.12161 0.50000 P 0.00000 0.00000 0.00000 1.00000 O 0.14839 0.08264 0.12584 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 0.02040 0.02040 0.01410 0.00000 0.00000 0.00000 H 0.02230 0.02490 0.02680 -0.00050 -0.00190 -0.00200 P 0.01060 0.01060 0.01380 0.00000 0.00000 0.00000 O 0.01440 0.01420 0.01860 0.00190 -0.00540 -0.00390