data_global _chemical_name_mineral 'Covellite' loop_ _publ_author_name 'Fjellvag H' 'Gronvold F' 'Stolen S' 'Andresen A F' 'Mueller-Kaefer R' 'Simon A' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 184 _journal_year 1988 _journal_page_first 111 _journal_page_last 121 _publ_section_title ; Low-temperature structural distortion in CuS Sample: T = 55 K Note: Cell parameters estimated from Figure 1 ; _database_code_amcsd 0010980 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Cu S' _cell_length_a 3.782 _cell_length_b 3.782 _cell_length_c 16.29 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 201.788 _exptl_crystal_density_diffrn 4.721 _symmetry_space_group_name_H-M 'P 63/m m c' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-x+y,1/2+z' 'x,x-y,1/2-z' '-x+y,-x,1/2-z' 'x-y,x,1/2+z' '-y,-x,z' 'y,x,-z' 'y,-x+y,-z' '-y,x-y,z' 'x-y,-y,1/2+z' '-x+y,y,1/2-z' 'x,y,1/2-z' '-x,-y,1/2+z' 'x,x-y,z' '-x,-x+y,-z' 'x-y,x,-z' '-x+y,-x,z' 'y,x,1/2+z' '-y,-x,1/2-z' '-y,x-y,1/2-z' 'y,-x+y,1/2+z' '-x+y,y,z' 'x-y,-y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Cu1 0.33333 0.66667 0.75000 Cu2 0.33333 0.66667 0.10680 S1 0.33333 0.66667 0.25000 S2 0.00000 0.00000 0.06240