data_global _chemical_name_mineral 'Carbon' loop_ _publ_author_name 'Ownby P D' 'Yang X' 'Liu J' _journal_name_full 'Journal of the American Ceramic Society' _journal_volume 75 _journal_year 1992 _journal_page_first 1876 _journal_page_last 1883 _publ_section_title ; Calculated X-ray diffraction data for diamond polytypes Note: hexagonal, 6H structure Note: theoretically calculated structure values ; _database_code_amcsd 0014068 _chemical_formula_sum 'C' _cell_length_a 2.5221 _cell_length_b 2.5221 _cell_length_c 12.3557 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 68.065 _exptl_crystal_density_diffrn 3.516 _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 C1 0.00000 0.00000 0.18750 C2 0.33333 0.66667 0.52083 C3 0.33333 0.66667 0.64583