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_4126637
_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_moiety         'C10 H16 N, C2 Cl3 O2'
_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           29
_space_group_name_H-M_alt        'P b 21 a'
_symmetry_space_group_name_Hall  'P -2a -2ab'
_symmetry_space_group_name_H-M   'P b 21 a'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.1923(6)
_cell_length_b                   17.8181(4)
_cell_length_c                   8.7142(2)
_cell_measurement_reflns_used    5828
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.5330
_cell_measurement_theta_min      3.9420
_cell_volume                     2980.00(13)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 10.5594
_diffrn_measured_fraction_theta_full 0.975
_diffrn_measured_fraction_theta_max 0.999
_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  0.0262
_diffrn_reflns_av_unetI/netI     0.0277
_diffrn_reflns_Laue_measured_fraction_full 0.975
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            11742
_diffrn_reflns_point_group_measured_fraction_full 0.792
_diffrn_reflns_point_group_measured_fraction_max 0.811
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         24.998
_diffrn_reflns_theta_min         2.810
_diffrn_source                   'SuperNova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.608
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.49511
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.394
_exptl_crystal_description       block
_exptl_crystal_F_000             1296
_exptl_crystal_size_max          0.43
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.27
_refine_diff_density_max         0.762
_refine_diff_density_min         -0.739
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details
;
 Flack x determined using 1426 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   0.46(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.030
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     329
_refine_ls_number_reflns         4266
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0357
_refine_ls_R_factor_gt           0.0325
_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^)+(0.0316P)^2^+2.3845P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0734
_refine_ls_wR_factor_ref         0.0756
_reflns_Friedel_coverage         0.568
_reflns_Friedel_fraction_full    0.596
_reflns_Friedel_fraction_max     0.610
_reflns_number_gt                4057
_reflns_number_total             4266
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b08950_si_002.cif
_cod_data_source_block           100K
_cod_database_code               4126637
_shelxl_version_number           2013-2
_shelx_res_checksum              24655
_shelx_hkl_checksum              63161