data_global _chemical_name_mineral 'Cuprite' loop_ _publ_author_name 'Hafner S S' 'Nagel S' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 9 _journal_year 1983 _journal_page_first 19 _journal_page_last 22 _publ_section_title ; The electric field gradient at the position of copper in Cu2O and electronic charge density analysis by means of K-factors ; _database_code_amcsd 0007351 _chemical_formula_sum 'Cu2 O' _cell_length_a 4.2696 _cell_length_b 4.2696 _cell_length_c 4.2696 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 77.833 _exptl_crystal_density_diffrn 6.106 _symmetry_space_group_name_H-M 'P n 3' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+z,1/2+x,1/2-y' '1/2+z,1/2-x,1/2+y' '1/2-z,1/2+x,1/2+y' '1/2-z,1/2-x,1/2-y' 'y,-z,-x' '-y,-z,x' '-y,z,-x' 'y,z,x' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2+y,1/2-z' '1/2-x,1/2-y,1/2-z' '-z,-x,y' '-z,x,-y' 'z,-x,-y' 'z,x,y' '1/2-y,1/2+z,1/2+x' '1/2+y,1/2+z,1/2-x' '1/2+y,1/2-z,1/2+x' '1/2-y,1/2-z,1/2-x' '-x,y,-z' 'x,-y,-z' '-x,-y,z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Cu 0.25000 0.25000 0.25000 O 0.00000 0.00000 0.00000