New Ferroelectrics Based on Divalent Metal Ion Alum
Wen Zhang; Li-Zhuang Chen; Ren-Gen Xiong; Takayoshi Nakamura; Songping D. Huang; Journal of the American Chemical Society 131 (2009) 12544–12545; doi:10.1021/ja905399x

data_4104999
_publ_section_title
;
 New Ferroelectrics Based on Divalent Metal Ion Alum
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              12544
_journal_page_last               12545
_journal_paper_doi               10.1021/ja905399x
_journal_volume                  131
_journal_year                    2009
_chemical_formula_sum            'C6 H26 Cu N2 O14 Se2'
_chemical_formula_weight         571.75
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 124.84(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.1294(14)
_cell_length_b                   12.629(3)
_cell_length_c                   12.142(4)
_cell_measurement_temperature    293(2)
_cell_volume                     897.3(5)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_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  0.0440
_diffrn_reflns_av_sigmaI/netI    0.0351
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            9165
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         3.23
_exptl_absorpt_coefficient_mu    5.345
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8521
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_density_diffrn    2.116
_exptl_crystal_F_000             570
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.518
_refine_diff_density_min         -0.863
_refine_diff_density_rms         0.100
_refine_ls_extinction_coef       0.0196(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.106
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     144
_refine_ls_number_reflns         2051
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.106
_refine_ls_R_factor_all          0.0437
_refine_ls_R_factor_gt           0.0345
_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^)+(0.0222P)^2^+2.2139P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0753
_refine_ls_wR_factor_ref         0.0786
_reflns_number_gt                1752
_reflns_number_total             2051
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja905399x_si_002.cif
_cod_data_source_block           1
_cod_original_cell_volume        897.3(4)
_cod_original_sg_symbol_H-M      'P 21/c '
_cod_database_code               4104999