data_global _chemical_name_mineral 'Archerite' loop_ _publ_author_name 'Levy H A' 'Peterson S W' 'Simonsen S H' _journal_name_full 'Physical Review' _journal_volume 93 _journal_year 1954 _journal_page_first 1120 _journal_page_last 1121 _publ_section_title ; Neutron diffraction study of the ferroelectric modification of potassium dihydrogen phosphate Note sample at T = 113 K Note: low temperature polymorph of archerite ; _database_code_amcsd 0015150 _chemical_formula_sum 'K P O4 H2' _cell_length_a 10.53 _cell_length_b 10.44 _cell_length_c 6.90 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 758.539 _exptl_crystal_density_diffrn 2.383 _symmetry_space_group_name_H-M 'F d d 2' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2+y,1/2+z' '1/2+x,y,1/2+z' '1/2+x,1/2+y,z' '1/4+x,1/4-y,1/4+z' '1/4+x,3/4-y,3/4+z' '3/4+x,1/4-y,3/4+z' '3/4+x,3/4-y,1/4+z' '1/4-x,1/4+y,1/4+z' '1/4-x,3/4+y,3/4+z' '3/4-x,1/4+y,3/4+z' '3/4-x,3/4+y,1/4+z' '-x,1/2-y,1/2+z' '-x,-y,+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 K 0.00000 0.00000 0.51200 0.00507 P 0.00000 0.00000 0.00000 0.00760 O1 0.11600 0.03450 0.13100 0.00760 O2 -0.03450 0.11600 -0.12350 0.00760 H 0.18800 -0.03750 0.13350 0.02533