data_global _chemical_name_mineral 'Svenekite' loop_ _publ_author_name 'Ferraris G' 'Jones D W' 'Yerkess J' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 28 _journal_year 1972 _journal_page_first 2430 _journal_page_last 2437 _publ_section_title ; A neutron diffraction study of the crystal structure of calcium bis(dihydrogen arsenate), Ca(H2AsO4)2 ; _database_code_amcsd 0018340 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'As2 Ca O8 H4' _cell_length_a 8.558 _cell_length_b 7.697 _cell_length_c 5.721 _cell_angle_alpha 92.35 _cell_angle_beta 109.52 _cell_angle_gamma 109.59 _cell_volume 329.621 _exptl_crystal_density_diffrn 3.244 _symmetry_space_group_name_H-M 'P -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z As1 0.34157 0.23990 -0.01476 As2 0.18712 0.76648 0.33085 Ca1 0.08150 0.18660 0.31250 O1 0.17410 0.06170 0.00320 O2 0.37850 0.40140 0.23680 O3 0.54170 0.20820 0.07340 O4 0.31090 0.32520 -0.27930 O5 0.04540 0.67010 0.03060 O6 0.12550 0.90650 0.47590 O7 0.17010 0.56720 0.46650 O8 0.39710 0.85950 0.34050 H1 0.56720 0.17600 -0.07750 H2 0.48950 0.51510 0.27630 H3 0.25930 0.59930 0.63620 H4 0.00000 0.50000 0.00000 H5 0.50000 0.00000 0.50000 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 As1 0.00847 0.01049 0.01063 0.00214 0.00417 0.00252 As2 0.00924 0.01000 0.01113 0.00328 0.00367 0.00088 Ca1 0.01683 0.01442 0.01418 0.00531 0.00619 0.00279 O1 0.01277 0.01241 0.01481 0.00125 0.00583 0.00215 O2 0.01746 0.01721 0.01646 0.00228 0.00734 -0.00188 O3 0.01342 0.02290 0.01937 0.00821 0.00518 0.00404 O4 0.01669 0.01380 0.01266 0.00201 0.00405 0.00392 O5 0.02113 0.00949 0.01468 0.00455 0.00075 0.00125 O6 0.01720 0.01393 0.01634 0.00735 0.00847 0.00202 O7 0.01962 0.01556 0.01735 0.00708 0.00494 0.00619 O8 0.01177 0.02076 0.02090 0.00328 0.00810 -0.00075 H1 0.02076 0.03546 0.03583 0.01177 0.01139 0.00152 H2 0.02531 0.01988 0.03114 -0.00087 0.00595 -0.00354 H3 0.03660 0.04875 0.02658 0.01911 0.00290 0.01292 H4 0.02875 0.03800 0.02343 0.01228 0.00506 0.00646 H5 0.03341 0.04255 0.04052 0.02125 0.02000 0.01684