data_global _chemical_name_mineral 'Nierite' loop_ _publ_author_name 'Billy M' 'Labbe J' 'Selvaraj A' 'Roult G' _journal_name_full 'Materials Research Bulletin' _journal_volume 18 _journal_year 1983 _journal_page_first 921 _journal_page_last 934 _publ_section_title ; Modifications structurales du nitrure de silicium en fonction de la temperature _cod_database_code 1001238 ; _database_code_amcsd 0014301 _chemical_formula_sum 'N4 Si3' _cell_length_a 7.7523 _cell_length_b 7.7523 _cell_length_c 5.6198 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 292.491 _exptl_crystal_density_diffrn 3.186 _symmetry_space_group_name_H-M 'P 3 1 c' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x-y,-y,1/2+z' '-y,x-y,z' 'y,x,1/2+z' '-x+y,-x,z' '-x,-x+y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z N1 0.00000 0.00000 0.50000 N2 0.33333 0.66667 0.63510 N3 0.65330 0.61090 0.45920 N4 0.31690 0.31980 0.72880 Si1 0.08210 0.50890 0.68280 Si2 0.25630 0.17120 0.47260