White-Light Emission and Structural Distortion in New Corrugated Two-Dimensional Lead Bromide Perovskites.
Mao, Lingling; Wu, Yilei; Stoumpos, Constantinos C.; Wasielewski, Michael R.; Kanatzidis, Mercouri G.; Journal of the American Chemical Society 139 (2017) 5210–5215; doi:10.1021/jacs.7b01312

data_4131237
_publ_section_title
;
 White-Light Emission and Structural Distortion in New Corrugated
 Two-Dimensional Lead Bromide Perovskites.
;
_journal_issue                   14
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5210
_journal_page_last               5215
_journal_paper_doi               10.1021/jacs.7b01312
_journal_volume                  139
_journal_year                    2017
_chemical_formula_moiety         '0.13(Br32 Pb8), C4 H14 N2'
_chemical_formula_sum            'C4 H14 Br4 N2 Pb'
_chemical_formula_weight         617.00
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            16
_cell_length_a                   18.901(4)
_cell_length_b                   11.782(2)
_cell_length_c                   23.680(5)
_cell_measurement_reflns_used    14763
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      29.38
_cell_measurement_theta_min      1.72
_cell_volume                     5273.3(18)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2008)'
_computing_structure_solution    'XT (Sheldrick, 2015)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector                 'image plate (34 cm diameter)'
_diffrn_detector_area_resol_mean 6.67
_diffrn_detector_type            STOE
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device       '2-circle goniometer'
_diffrn_measurement_device_type  'STOE IPDS 2'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1326
_diffrn_reflns_av_unetI/netI     0.0775
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            48443
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         29.225
_diffrn_reflns_theta_min         1.720
_diffrn_source
'sealed X-ray tube, 12 x 0.4 mm long-fine focus'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    24.878
_exptl_absorpt_correction_T_max  0.4416
_exptl_absorpt_correction_T_min  0.1503
_exptl_absorpt_correction_type   integration
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.109
_exptl_crystal_description       plate
_exptl_crystal_F_000             4384
_exptl_crystal_size_max          0.0825
_exptl_crystal_size_mid          0.0523
_exptl_crystal_size_min          0.0225
_refine_diff_density_max         2.419
_refine_diff_density_min         -1.604
_refine_diff_density_rms         0.262
_refine_ls_extinction_coef       0.00064(3)
_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   1.090
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     184
_refine_ls_number_reflns         7132
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.090
_refine_ls_R_factor_all          0.1366
_refine_ls_R_factor_gt           0.0789
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0540P)^2^+53.6400P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1415
_refine_ls_wR_factor_ref         0.1628
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4348
_reflns_number_total             7132
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b01312_si_002.cif
_cod_data_source_block           1
_cod_database_code               4131237
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups, All N(H) groups, All N(H,H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 C1-C2
 1.5 with sigma of 0.02
3. Uiso/Uaniso restraints and constraints
Uanis(C1) = Uanis(C2)
Uanis(N1) = Uanis(C1)
Uanis(C1) = Uanis(C2)
4.a Ternary CH refined with riding coordinates:
 N2(H2), N4(H4)
4.b Secondary CH2 refined with riding coordinates:
 C1(H1D,H1E), C2(H2A,H2B), C5(H5A,H5B), C6(H6A,H6B)
4.c Idealised Me refined as rotating group:
 N1(H1A,H1B,H1C), C3(H3A,H3B,H3C), C4(H4A,H4B,H4C), N3(H3D,H3E,H3F), C7(H7A,
 H7B,H7C), C8(H8A,H8B,H8C)
;
_olex2_submission_special_instructions 'No special instructions were received'