A spiro-type ammonium based switchable dielectric material with two sequential reversible phase transitions above room temperature
Wang, Xiao-Li; Zhou, Lin; Ye, Qiong; Geng, Fu-Juan; Ye, Heng-Yun; Fu, Da-Wei; Zhang, Yi; RSC Adv.  (2016) –; doi:10.1039/C6RA14157A

data_7226055
_publ_section_title
;
 A spiro-type ammonium based switchable dielectric material with two
 sequential reversible phase transitions above room temperature
;
_journal_name_full               'RSC Adv.'
_journal_paper_doi               10.1039/C6RA14157A
_journal_year                    2016
_chemical_formula_moiety         '2(C8 H16 N), Br4 Cd'
_chemical_formula_sum            'C16 H32 Br4 Cd N2'
_chemical_formula_weight         684.45
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2016-05-30 deposited with the CCDC.
2016-07-26 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.407(12)
_cell_length_b                   18.17(2)
_cell_length_c                   14.370(17)
_cell_measurement_reflns_used    14299
_cell_measurement_temperature    348(2)
_cell_measurement_theta_max      24.996
_cell_measurement_theta_min      2.588
_cell_volume                     2456(5)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      348(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'not measured'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0941
_diffrn_reflns_av_unetI/netI     0.1015
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            14299
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        24.996
_diffrn_reflns_theta_max         24.996
_diffrn_reflns_theta_min         2.588
_exptl_absorpt_coefficient_mu    7.398
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.851
_exptl_crystal_description       block
_exptl_crystal_F_000             1320
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         1.282
_refine_diff_density_min         -0.981
_refine_diff_density_rms         0.175
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.57(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.216
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         4319
_refine_ls_number_restraints     169
_refine_ls_restrained_S_all      1.776
_refine_ls_R_factor_all          0.2598
_refine_ls_R_factor_gt           0.1482
_refine_ls_shift/su_max          0.015
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.2000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3791
_refine_ls_wR_factor_ref         0.4467
_reflns_Friedel_coverage         0.756
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.999
_reflns_number_gt                1860
_reflns_number_total             4319
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6ra14157a2.cif
_cod_data_source_block           2
_cod_database_code               7226055
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              53398