Sodium tungstate dihydrate: a redetermination
Farrugia, Louis J.; Acta Crystallographica Section E 63 (2007) i142–i142; doi:10.1107/S1600536807023355

data_2213903
_publ_section_title
;
 Sodium tungstate dihydrate: a redetermination
;
_journal_coeditor_code           MG2024
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i142
_journal_page_last               i142
_journal_paper_doi               10.1107/S1600536807023355
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'Na2 W O4. 2H2 O'
_chemical_formula_moiety         '(Na +)2, O4 W 2-, 2(H2 O)'
_chemical_formula_sum            'H4 Na2 O6 W'
_chemical_formula_weight         329.86
_chemical_name_systematic
;
 ?
;
_space_group_crystal_system      orthorhombic
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   8.4797(5)
_cell_length_b                   10.5930(5)
_cell_length_c                   13.8527(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    291(2)
_cell_measurement_theta_max      24.92
_cell_measurement_theta_min      21.10
_cell_volume                     1244.33(13)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection       'CAD-4 EXPRESS (Enraf-Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1985)'
_diffrn_ambient_temperature      291(2)
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 1
_diffrn_measurement_device       'Enraf Nonius TurboCAD4'
_diffrn_measurement_method       'non-profiled \w/2\q scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0274
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            7543
_diffrn_reflns_reduction_process
;
 Merged with SORTAV
 R.H. Blessing, (1987) Cryst. Rev. 1, 3-58
 R.H. Blessing, (1989) J. Appl. Cryst. 22, 396-397
;
_diffrn_reflns_theta_full        29.98
_diffrn_reflns_theta_max         29.98
_diffrn_reflns_theta_min         2.94
_diffrn_standards_decay_%        1
_diffrn_standards_interval_time  120
_diffrn_standards_number         6
_exptl_absorpt_coefficient_mu    18.664
_exptl_absorpt_correction_T_max  0.1475
_exptl_absorpt_correction_T_min  0.0208
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
;
(de Meulenaer & Tompa, 1965; Alcock, 1970)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.522
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.391
_exptl_crystal_size_mid          0.344
_exptl_crystal_size_min          0.109
_refine_diff_density_max         2.752
_refine_diff_density_min         -1.48
_refine_ls_extinction_coef       0.00228(11)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.256
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     97
_refine_ls_number_reflns         1811
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.255
_refine_ls_R_factor_all          0.023
_refine_ls_R_factor_gt           0.0207
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0230P)^2^+2.0063P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0532
_reflns_number_gt                1664
_reflns_number_total             1811
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            mg2024.cif
_cod_data_source_block           I
_cod_database_code               2213903
_cod_database_fobs_code          2213903