data_global _amcsd_formula_title 'K6 Nb6 O26 Si4' loop_ _publ_author_name 'Choisnet J' 'Nguyen N' 'Groult D' 'Raveau B' _journal_name_full 'Materials Research Bulletin' _journal_volume 11 _journal_year 1976 _journal_page_first 887 _journal_page_last 894 _publ_section_title ; De nouveaux oxydes a reseau forme d'octaedres Nb O6 (Ta O6) et de groupes Si2 O7: Les phases A3 Ta6 Si4 O26 (A= Ba, Sr) et K6 M6 Si4 O26 (M= Nb, Ta) _cod_database_code 1001105 ; _database_code_amcsd 0014250 _chemical_formula_sum 'K3 Nb3 Si2 O13' _cell_length_a 9.032 _cell_length_b 9.032 _cell_length_c 8.041 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 568.079 _exptl_crystal_density_diffrn 3.859 _symmetry_space_group_name_H-M 'P -6 2 m' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-x+y,z' '-x+y,-x,-z' 'y,x,-z' '-y,x-y,z' 'x-y,-y,z' 'x,y,-z' '-x,-x+y,-z' '-x+y,-x,z' 'y,x,z' '-y,x-y,-z' 'x-y,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z K1 0.59100 0.00000 0.50000 K2 0.60400 0.00000 0.00000 Nb1 0.23900 0.00000 0.23400 Si1 0.33333 0.66667 0.20300 O1 0.33333 0.66667 0.00000 O2 0.25000 0.00000 0.00000 O3 0.81600 0.00000 0.23700 O4 0.49400 0.17600 0.26500 O5 0.26800 0.00000 0.50000