data_global _chemical_name_mineral 'Ahlfeldite' loop_ _publ_author_name 'Wildner M' _journal_name_full 'Neues Jahrbuch fur Mineralogie, Monatshefte' _journal_volume 1990 _journal_year 1990 _journal_page_first 353 _journal_page_last 362 _publ_section_title ; Crystal structure refinements of synthetic cobaltomenite (CoSeO3*2H2O) and ahlfeldite (NiSeO3*2H2O) ; _database_code_amcsd 0014846 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Ni Se O5 H4' _cell_length_a 6.441 _cell_length_b 8.746 _cell_length_c 7.522 _cell_angle_alpha 90 _cell_angle_beta 99.00 _cell_angle_gamma 90 _cell_volume 418.520 _exptl_crystal_density_diffrn 3.518 _symmetry_space_group_name_H-M 'P 1 21/n 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2-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 Ni 0.35246 0.63816 0.51806 0.01920 Se 0.60100 0.15084 0.83718 0.01790 O1 0.67040 0.32570 0.76500 0.02230 O2 0.67180 0.59170 0.53280 0.01940 O3 0.45840 0.19740 0.99920 0.02390 Ow1 0.38310 0.56660 0.79110 0.02560 Ow2 0.42100 0.85920 0.57750 0.02690 H11 0.48100 0.50200 0.78900 0.02350 H12 0.40000 0.64800 0.89700 0.02350 H21 0.34900 0.89800 0.65200 0.02350 H22 0.56800 0.87700 0.62000 0.02350 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 Ni 0.01440 0.02700 0.01640 0.00080 0.00290 0.00000 Se 0.01330 0.02600 0.01440 0.00000 0.00210 -0.00040 O1 0.02420 0.02430 0.01710 0.00050 -0.00110 0.00530 O2 0.01330 0.02150 0.02360 0.00180 0.00360 -0.00070 O3 0.01520 0.03530 0.02270 -0.00340 0.00720 -0.00480 Ow1 0.02330 0.03940 0.01510 0.00850 0.00620 -0.00180 Ow2 0.02570 0.03090 0.02290 0.00230 0.00040 -0.00560