Origin of spontaneous polarization and reconstructive phase transition in guanidinium iodide
Szafrański, Marek; Jarek, Marcin; CrystEngComm 15 (2013) 4617–; doi:10.1039/c3ce26979e

data_7210074
_publ_section_title
;
 Origin of spontaneous polarization and reconstructive phase transition in
 guanidinium iodide
;
_journal_issue                   23
_journal_name_full               CrystEngComm
_journal_page_first              4617
_journal_paper_doi               10.1039/c3ce26979e
_journal_volume                  15
_journal_year                    2013
_chemical_formula_sum            'C H6 I N3'
_chemical_formula_weight         186.99
_chemical_melting_point          460(5)
_chemical_name_common            'guanidinium iodide'
_chemical_name_systematic
;
?
;
_space_group_IT_number           186
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_Hall  'P 6c -2c'
_symmetry_space_group_name_H-M   'P 63 m c'
_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                120.00
_cell_formula_units_Z            4
_cell_length_a                   7.21109(19)
_cell_length_b                   7.21109(19)
_cell_length_c                   12.4610(5)
_cell_measurement_temperature    340.0(1)
_cell_volume                     561.16(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      340.0(1)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'Gemini A Ultra'
_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  0.0232
_diffrn_reflns_av_sigmaI/netI    0.0106
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            7972
_diffrn_reflns_theta_full        32.31
_diffrn_reflns_theta_max         32.31
_diffrn_reflns_theta_min         3.26
_exptl_absorpt_coefficient_mu    5.563
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.78053
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysalisPro (Oxford Diffraction 2010)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.213
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             344
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.251
_refine_diff_density_min         -0.377
_refine_diff_density_rms         0.056
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.04(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.183
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     28
_refine_ls_number_reflns         789
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.183
_refine_ls_R_factor_all          0.0254
_refine_ls_R_factor_gt           0.0206
_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^)+(0.0234P)^2^+0.0530P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0479
_refine_ls_wR_factor_ref         0.0493
_reflns_number_gt                706
_reflns_number_total             789
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ce26979e.txt
_cod_data_source_block           ttgi_340d
_cod_original_sg_symbol_H-M      P6(3)mc
_cod_database_code               7210074