Structures and phase transitions in a new ferroelectric ‒ pyridinium chlorochromate ‒ studied by X-ray diffraction, DSC and dielectric methods
Małuszyńska, Hanna; Czarnecki, Piotr; Czarnecka, Anna; Pajak, Zdzisław; Acta Crystallographica Section B 68 (2012) 128–136; doi:10.1107/S0108768112005782

data_2105072
_publ_section_title
;
 Structures and phase transitions in a new ferroelectric -- pyridinium
 chlorochromate -- studied by X-ray diffraction, DSC and dielectric
 methods
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              128
_journal_page_last               136
_journal_paper_doi               10.1107/S0108768112005782
_journal_volume                  68
_journal_year                    2012
_chemical_formula_moiety         '[C5H5 NH]+ [Cl Cr O3]- '
_chemical_formula_sum            'C5 H6 Cl Cr N O3'
_chemical_formula_weight         215.56
_chemical_name_systematic
;
 pyridinium chlorochromate
;
_space_group_IT_number           9
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 95.481(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3539(3)
_cell_length_b                   8.4985(3)
_cell_length_c                   12.9706(6)
_cell_measurement_reflns_used    2913
_cell_measurement_temperature    120.0(2)
_cell_measurement_theta_max      28.1611
_cell_measurement_theta_min      2.3917
_cell_volume                     806.92(6)
_computing_cell_refinement       'CrysAlisPro, Oxford Diffraction Ltd., 2010'
_computing_data_collection       'CrysAlisPro, Oxford Diffraction Ltd., 2010'
_computing_data_reduction        'CrysAlisPro, Oxford Diffraction Ltd., 2010'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      120.0(2)
_diffrn_detector_area_resol_mean 10.3200
_diffrn_measured_fraction_theta_full 0.952
_diffrn_measured_fraction_theta_max 0.952
_diffrn_measurement_device_type  'Xcalibur, Atlas, Gemini ultra'
_diffrn_measurement_method       'omega scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0266
_diffrn_reflns_av_sigmaI/netI    0.0256
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            5194
_diffrn_reflns_theta_full        28.19
_diffrn_reflns_theta_max         28.19
_diffrn_reflns_theta_min         3.16
_exptl_absorpt_coefficient_mu    1.703
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.86187
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.774
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             432
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.373
_refine_diff_density_min         -0.229
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.831(17)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     125
_refine_ls_number_reflns         1845
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0282
_refine_ls_R_factor_gt           0.0257
_refine_ls_shift/su_max          0.025
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0356P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0612
_refine_ls_wR_factor_ref         0.0635
_reflns_number_gt                1718
_reflns_number_total             1845
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            eb5013.cif
_cod_data_source_block           120_enan
_cod_original_cell_volume        806.91(6)
_cod_original_sg_symbol_H-M      Cc
_cod_database_code               2105072
_cod_database_fobs_code          2105072