The Two-Dimensional AxCdxBi4-xQ6 (A = K, Rb, Cs; Q = S, Se): Direct Bandgap Semiconductors and Ion-Exchange Materials.
Zhao, Jing; Islam, Saiful M.; Kontsevoi, Oleg Y.; Tan, Gangjian; Stoumpos, Constantinos C.; Chen, Haijie; Li, Rukang; Kanatzidis, Mercouri G.; Journal of the American Chemical Society  (2017) –; doi:10.1021/jacs.7b02243

data_4126032
_publ_section_title
;
 The Two-Dimensional AxCdxBi4-xQ6 (A = K, Rb, Cs; Q = S, Se): Direct
 Bandgap Semiconductors and Ion-Exchange Materials.
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_paper_doi               10.1021/jacs.7b02243
_journal_year                    2017
_chemical_formula_sum            'Bi5.74 Cd2.26 Cs2.27 Se12'
_chemical_formula_weight         2701.10
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           63
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-C 2c 2'
_symmetry_space_group_name_H-M   'C m c m'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   4.1363(8)
_cell_length_b                   7.1476(14)
_cell_length_c                   25.047(5)
_cell_measurement_reflns_used    3016
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      32.05
_cell_measurement_theta_min      3.25
_cell_volume                     740.5(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 6.67
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_device_type  'STOE IPDS 2T'
_diffrn_measurement_method       'rotation method'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0993
_diffrn_reflns_av_sigmaI/netI    0.0440
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            1925
_diffrn_reflns_theta_full        24.98
_diffrn_reflns_theta_max         24.98
_diffrn_reflns_theta_min         3.25
_exptl_absorpt_coefficient_mu    53.076
_exptl_absorpt_correction_T_max  0.2790
_exptl_absorpt_correction_T_min  0.0264
_exptl_absorpt_correction_type   integration
_exptl_crystal_colour            Black
_exptl_crystal_density_diffrn    6.057
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Bulk
_exptl_crystal_F_000             1117
_exptl_crystal_size_max          0.1130
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.0059
_refine_diff_density_max         1.904
_refine_diff_density_min         -1.864
_refine_diff_density_rms         0.424
_refine_ls_extinction_coef       0.0008(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.226
_refine_ls_matrix_type           full
_refine_ls_number_parameters     27
_refine_ls_number_reflns         375
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.222
_refine_ls_R_factor_all          0.0569
_refine_ls_R_factor_gt           0.0488
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0357P)^2^+39.6255P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1029
_refine_ls_wR_factor_ref         0.1078
_reflns_number_gt                309
_reflns_number_total             375
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja7b02243_si_005.cif
_cod_data_source_block           2.Cs1.13Cd1.13Bi2.87Se6
_cod_original_sg_symbol_H-M      Cmcm
_cod_original_formula_sum        ' Bi5.74 Cd2.26 Cs2.27 Se12'
_cod_database_code               4126032