data_global _chemical_name_mineral 'Ludlamite' loop_ _publ_author_name 'Abrahams S C' _journal_name_full 'Journal of Chemical Physics' _journal_volume 44 _journal_year 1966 _journal_page_first 2230 _journal_page_last 2237 _publ_section_title ; Ferromagnetic and crystal structure of ludlamite, Fe3(PO4)2*4(H2O), at 4.2 K Sample: T = 4.2 K ; _database_code_amcsd 0012982 _chemical_formula_sum 'Fe3 P2 O12 H8' _cell_length_a 10.541 _cell_length_b 4.638 _cell_length_c 9.285 _cell_angle_alpha 90 _cell_angle_beta 100.728 _cell_angle_gamma 90 _cell_volume 446.002 _exptl_crystal_density_diffrn 3.199 _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 Fe1 0.00000 0.00000 0.00000 0.00228 Fe2 0.17270 0.07290 0.32870 0.00329 P 0.45240 0.97240 0.23720 0.00380 O1 0.03530 0.78370 0.20030 0.00811 O2 0.40860 0.15440 0.09890 0.00494 O3 0.33240 0.85150 0.29190 0.00418 O4 0.03440 0.35510 0.35960 0.00887 O5 0.17020 0.24120 0.09920 0.00494 O6 0.32650 0.38460 0.45390 0.00481 H1 0.14290 0.43210 0.06390 0.02862 H2 0.26500 0.20350 0.09180 0.02026 H3 0.33040 0.56760 0.39530 0.01798 H4 0.40640 0.27800 0.44430 0.01684