data_global _chemical_name_mineral 'Sklodowskite' loop_ _publ_author_name 'Mokeeva V I' _journal_name_full 'Soviet Physics Doklady' _journal_volume 4 _journal_year 1959 _journal_page_first 27 _journal_page_last 29 _publ_section_title ; The crystal structure of sklodowskite ; _database_code_amcsd 0015594 _chemical_formula_sum 'Mg U2 Si2 O16 H8' _cell_length_a 16.74 _cell_length_b 7.01 _cell_length_c 6.59 _cell_angle_alpha 90 _cell_angle_beta 96 _cell_angle_gamma 90 _cell_volume 769.083 _exptl_crystal_density_diffrn 3.543 _symmetry_space_group_name_H-M 'I 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,-y,z' '1/2+x,1/2-y,1/2+z' '-x,y,-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Mg 0.00000 0.00000 0.50000 U 0.25900 0.00000 0.11500 Si 0.21900 0.00000 0.58800 OSi1 0.27300 0.00000 0.80000 OSi2 0.12500 0.00000 0.62500 OSi3 0.24000 0.18700 0.44200 OU1 0.14300 0.00000 0.03800 OU2 0.37300 0.00000 0.18900 Wat 0.02700 0.20800 0.30400