Unusual Long-Range Ordering Incommensurate Structural Modulations in an Organic Molecular Ferroelectric.
Sun, Zhihua; Li, Jian; Ji, Chengmin; Sun, Junliang; Hong, Maochun; Luo, Junhua; Journal of the American Chemical Society  (2017) –; doi:10.1021/jacs.7b08950

data_4126634
_publ_section_title
;
 Unusual Long-Range Ordering Incommensurate Structural Modulations in an
 Organic Molecular Ferroelectric.
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_paper_doi               10.1021/jacs.7b08950
_journal_year                    2017
_chemical_formula_sum            'C12 H16 Cl3 N O2'
_chemical_formula_weight         312.61
_chemical_name_systematic
;
 ?
;
_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'
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   difmap
_audit_creation_method           SHELXL-2013
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_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.425(4)
_cell_length_b                   18.198(4)
_cell_length_c                   8.8148(18)
_cell_measurement_reflns_used    5658
_cell_measurement_temperature    290(2)
_cell_measurement_theta_max      27.5127
_cell_measurement_theta_min      2.5388
_cell_volume                     3116.0(11)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      290(2)
_diffrn_detector_area_resol_mean 4017
_diffrn_measured_fraction_theta_full 0.963
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0192
_diffrn_reflns_av_unetI/netI     0.0103
_diffrn_reflns_Laue_measured_fraction_full 0.963
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            18230
_diffrn_reflns_point_group_measured_fraction_full 0.963
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.000
_diffrn_reflns_theta_min         3.218
_exptl_absorpt_coefficient_mu    0.582
_exptl_absorpt_correction_T_max  0.885
_exptl_absorpt_correction_T_min  0.762
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.333
_exptl_crystal_description       block
_exptl_crystal_F_000             1296
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.29
_refine_diff_density_max         0.303
_refine_diff_density_min         -0.293
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     266
_refine_ls_number_reflns         2724
_refine_ls_number_restraints     43
_refine_ls_restrained_S_all      1.152
_refine_ls_R_factor_all          0.0808
_refine_ls_R_factor_gt           0.0721
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 w=1/[\s^2^(Fo^2^)+(0.0697P)^2^+2.0972P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1763
_refine_ls_wR_factor_ref         0.1836
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2348
_reflns_number_total             2724
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b08950_si_002.cif
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_cod_database_code               4126634
_shelxl_version_number           2013-2
_shelx_res_checksum              41767
_shelx_hkl_checksum              32849