data_global _amcsd_formula_title 'Cu3 O21 Rb Ta7' loop_ _publ_author_name 'Benmoussa A' 'Groult D' 'Studer F' 'Raveau B' _journal_name_full 'Journal of Solid State Chemistry' _journal_volume 41 _journal_year 1982 _journal_page_first 221 _journal_page_last 226 _publ_section_title ; Intergrowth of Hexagonal Tungsten Bronze and Perovskite-like Structures: The Oxides A Cu3 M7 O21 (A = K, Rb, Cs, Tl; M = Nb, Ta) _cod_database_code 1001218 ; _database_code_amcsd 0013465 _chemical_formula_sum 'Rb Cu3 Ta7 O21' _cell_length_a 28.11 _cell_length_b 7.503 _cell_length_c 7.548 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1591.944 _exptl_crystal_density_diffrn 7.839 _symmetry_space_group_name_H-M 'C m m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,z' '1/2+x,1/2-y,z' '-x,y,-z' '1/2-x,1/2+y,-z' '-x,y,z' '1/2-x,1/2+y,z' 'x,-y,-z' '1/2+x,1/2-y,-z' 'x,y,-z' '1/2+x,1/2+y,-z' '-x,-y,z' '1/2-x,1/2-y,z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Rb1 0.00000 0.00000 0.00000 1.00000 Rb2 0.00000 0.00000 0.50000 1.00000 Cu1 0.17300 0.00000 0.50000 1.00000 Cu2 0.32100 0.00000 0.50000 0.50000 Cu3 0.31800 0.00000 0.00000 1.00000 Cu4 0.18300 0.00000 0.00000 0.50000 Ta1 0.00000 0.50000 0.24400 1.00000 Ta2 0.11310 0.24770 0.25500 1.00000 Ta3 0.25000 0.25000 0.25200 1.00000 O1 0.08800 0.00000 0.24800 1.00000 O2 0.27400 0.00000 0.22000 1.00000 O3 0.36600 0.00000 0.20200 1.00000 O4 0.17900 0.16400 0.28000 1.00000 O5 0.04600 0.30400 0.28000 1.00000 O6 0.12400 0.32200 0.50000 1.00000 O7 0.12800 0.18700 0.00000 1.00000 O8 0.23600 0.32300 0.50000 0.50000 O9 0.23800 0.18600 0.00000 0.50000 O10 0.50000 0.00000 0.50000 1.00000 O11 0.50000 0.00000 0.00000 1.00000