data_global _chemical_name_mineral 'Lonsdaleite' loop_ _publ_author_name 'Yeh C' 'Lu Z' 'Froyen S' 'Zunger A' _journal_name_full 'Physical Review' _journal_volume B46 _journal_year 1992 _journal_page_first 10086 _journal_page_last 10097 _publ_section_title ; Zinc-blende-Wurtzite polytypism in semiconductors _cod_database_code 1100004 ; _database_code_amcsd 0018218 _chemical_formula_sum 'C' _cell_length_a 2.49 _cell_length_b 2.49 _cell_length_c 4.144 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 22.251 _exptl_crystal_density_diffrn 3.585 _symmetry_space_group_name_H-M 'P 63 m c' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-x+y,1/2+z' 'x-y,x,1/2+z' '-y,-x,z' '-y,x-y,z' 'x-y,-y,1/2+z' '-x,-y,1/2+z' 'x,x-y,z' '-x+y,-x,z' 'y,x,1/2+z' 'y,-x+y,1/2+z' '-x+y,y,z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z C1 0.33333 0.66667 0.00000 C2 0.33333 0.66667 0.37400