(NH~4~)~2~[Mg~4~(H~2~O)~18~(H~2~W~12~O~42~)]^.^10H~2~O, a new compound containing chains formed by magnesium and paradodecahedral tungstate ions
Li, Jing; Wang, Ru-Ji; Torardi, Charlie C.; Acta Crystallographica Section C 55 (1999) 1388–1391; doi:10.1107/S0108270199006265

data_2008872
_publ_section_title
;
 (NH~4~)~2~[Mg~4~(H~2~O)~18~(H~2~W~12~O~42~)]^.^10H~2~O, a new compound
 containing chains formed by magnesium and paradodecahedral tungstate
 ions
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1388
_journal_page_last               1391
_journal_paper_doi               10.1107/S0108270199006265
_journal_volume                  55
_journal_year                    1999
_chemical_formula_moiety
'(NH4 )2 [Mg4 (H2 O)18 (H2 W12 O42 )], 10H2 O'
_chemical_formula_sum            'H66 Mg4 N2 O70 W12'
_chemical_formula_weight         3517.99
_chemical_name_systematic
;
ammonium magnesium paradodecatungstate dodehydrate
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 101.08(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   14.045(3)
_cell_length_b                   12.932(3)
_cell_length_c                   17.099(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13.5
_cell_measurement_theta_min      4.5
_cell_volume                     3047.8(11)
_computing_cell_refinement       CAD4/PC
_computing_data_collection       'CAD4/PC (Enraf-Nonius, 1992)'
_computing_data_reduction        'XCAD4/PC (Harms, 1997)'
_computing_molecular_graphics
'SCHAKAL92 (Keller, 1992) and ORTEX (McArdle, 1993)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device_type  'Enraf-Nonius CAD4'
_diffrn_measurement_method       \w-scan
_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  0.0704
_diffrn_reflns_av_sigmaI/netI    0.1458
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            5545
_diffrn_reflns_theta_max         24.97
_diffrn_reflns_theta_min         2.08
_diffrn_standards_decay_%        +-2.1
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    22.719
_exptl_absorpt_correction_T_max  0.506
_exptl_absorpt_correction_T_min  0.151
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North et al., 1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.833
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thin plate'
_exptl_crystal_F_000             3152
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.03
_refine_diff_density_max         3.927
_refine_diff_density_min         -3.139
_refine_ls_extinction_coef       0.000088(6)
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_ref   1.165
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     225
_refine_ls_number_reflns         5354
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.165
_refine_ls_R_factor_all          0.1255
_refine_ls_R_factor_gt           0.0716
_refine_ls_shift/su_max          0.029
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1125
_reflns_number_gt                3250
_reflns_number_total             5354
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            br1227.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2008872