An Unprecedented Biaxial Trilayered Hybrid Perovskite Ferroelectric with Directionally Tunable Photovoltaic Effects.
Wang, Sasa; Liu, Xitao; Li, Lina; Ji, Chengmin; Sun, Zhihua; Wu, Zhenyue; Hong, Maochun; Luo, Junhua; Journal of the American Chemical Society 141 (2019) 7693–7697; doi:10.1021/jacs.9b02558

data_4127235
_publ_section_title
;
 An Unprecedented Biaxial Trilayered Hybrid Perovskite Ferroelectric with
 Directionally Tunable Photovoltaic Effects.
;
_journal_issue                   19
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7693
_journal_page_last               7697
_journal_paper_doi               10.1021/jacs.9b02558
_journal_volume                  141
_journal_year                    2019
_chemical_formula_sum            'C8 H32 Br10 N4 Pb3'
_chemical_formula_weight         1605.05
_space_group_IT_number           139
_space_group_name_Hall           '-I 4 2'
_space_group_name_H-M_alt        'I 4/m m m'
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4 2'
_symmetry_space_group_name_H-M   'I 4/m m m'
_atom_sites_solution_hydrogens   geom
_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            2
_cell_length_a                   6.0080(15)
_cell_length_b                   6.0080(15)
_cell_length_c                   46.843(15)
_cell_measurement_reflns_used    2077
_cell_measurement_temperature    390(2)
_cell_measurement_theta_max      26.4652
_cell_measurement_theta_min      2.5371
_cell_volume                     1690.8(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      390(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0679
_diffrn_reflns_av_sigmaI/netI    0.0332
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       60
_diffrn_reflns_limit_l_min       -59
_diffrn_reflns_number            5638
_diffrn_reflns_theta_full        27.47
_diffrn_reflns_theta_max         27.47
_diffrn_reflns_theta_min         3.42
_exptl_absorpt_coefficient_mu    26.719
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    3.153
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       slice
_exptl_crystal_F_000             1408
_refine_diff_density_max         2.198
_refine_diff_density_min         -3.464
_refine_diff_density_rms         0.238
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     43
_refine_ls_number_reflns         653
_refine_ls_number_restraints     12
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.0623
_refine_ls_R_factor_gt           0.0475
_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^)+(0.0794P)^2^+28.4442P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1375
_refine_ls_wR_factor_ref         0.1518
_reflns_number_gt                520
_reflns_number_total             653
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja9b02558_si_003.cif
_cod_data_source_block           c:\users\wu\desktop\22\2
_cod_depositor_comments
'Adding full bibliography for 4127235--4127236.cif.'
_cod_original_sg_symbol_H-M      I4/mmm
_cod_database_code               4127235