(NH4)2Te2WO8: A New Polar Oxide with Second-Harmonic Generating, Ferroelectric, and Pyroelectric Properties
Kim, Jun-Ho; Baek, Jaewook; Halasyamani, P. Shiv; Chemistry of Materials 19 (2007) 5637–; doi:10.1021/cm7019334

data_4001454
_publ_section_title
;
 (NH4)2Te2WO8:&#x00A0; A New Polar Oxide with Second-Harmonic Generating,
 Ferroelectric, and Pyroelectric Properties
;
_journal_issue                   23
_journal_name_full               'Chemistry of Materials'
_journal_page_first              5637
_journal_paper_doi               10.1021/cm7019334
_journal_volume                  19
_journal_year                    2007
_chemical_formula_sum            'H8 N2 O8 Te2 W'
_chemical_formula_weight         603.13
_chemical_name_systematic
; 
 Ammonium tungsten tellurite 
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 99.188(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.9716(9)
_cell_length_b                   7.0279(9)
_cell_length_c                   9.4593(13)
_cell_measurement_reflns_used    1342
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      28.14
_cell_measurement_theta_min      2.96
_cell_volume                     457.52(10)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.966
_diffrn_measured_fraction_theta_max 0.966
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0373
_diffrn_reflns_av_sigmaI/netI    0.0724
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            2840
_diffrn_reflns_theta_full        28.33
_diffrn_reflns_theta_max         28.33
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    18.895
_exptl_absorpt_correction_T_max  0.9875
_exptl_absorpt_correction_T_min  0.5042
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'psi-scan, (north et al., 1968)'
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    4.378
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'hexagonal plates'
_exptl_crystal_F_000             528
_exptl_crystal_size_max          0.08
_exptl_crystal_size_mid          0.02
_exptl_crystal_size_min          0.02
_refine_diff_density_max         1.502
_refine_diff_density_min         -1.784
_refine_diff_density_rms         0.299
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.062(11)
_refine_ls_extinction_coef       0.0028(2)
_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   0.922
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     119
_refine_ls_number_reflns         2025
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.922
_refine_ls_R_factor_all          0.0359
_refine_ls_R_factor_gt           0.0318
_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^)+(0.0163P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0597
_refine_ls_wR_factor_ref         0.0607
_reflns_number_gt                1851
_reflns_number_total             2025
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cm7019334-file003.cif
_cod_data_source_block           4onab
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               4001454