Synthesis, molecular structure and chemical properties of a new tungstosilicate with an open Wells‒Dawson structure, α-[Si2W18O66]16-
Laronze, Nathalie; Marrot, Jérôme; Hervé, Gilbert; Chemical Communications (Cambridge, United Kingdom)  (2003) 2360–2361; doi:10.1039/b307276b

data_7113444
_publ_section_title
;
 Synthesis, molecular structure and chemical properties of a new
 tungstosilicate with an open Wells--Dawson structure, \a-[Si2W18O66]16-
;
_journal_coden_ASTM              CHCOFS
_journal_issue                   18
_journal_name_full
;
 Chemical Communications (Cambridge, United Kingdom)
;
_journal_page_first              2360
_journal_page_last               2361
_journal_paper_doi               10.1039/b307276b
_journal_year                    2003
_chemical_formula_sum            'K16 O86 Si2 W18'
_chemical_formula_weight         5367.08
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                94.9830(10)
_cell_angle_beta                 94.9870(10)
_cell_angle_gamma                111.0120(10)
_cell_formula_units_Z            2
_cell_length_a                   12.4908(2)
_cell_length_b                   15.50140(10)
_cell_length_c                   25.55530(10)
_cell_measurement_reflns_used    10345
_cell_measurement_temperature    296(2)
_cell_volume                     4564.42(9)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_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 0.862
_diffrn_measured_fraction_theta_max 0.862
_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  0.0982
_diffrn_reflns_av_sigmaI/netI    0.0988
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            30505
_diffrn_reflns_theta_full        29.36
_diffrn_reflns_theta_max         29.36
_diffrn_reflns_theta_min         0.81
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    23.444
_exptl_absorpt_correction_T_max  0.4540
_exptl_absorpt_correction_T_min  0.0790
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.911
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             4712
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.04
_refine_diff_density_max         3.589
_refine_diff_density_min         -3.912
_refine_diff_density_rms         0.649
_refine_ls_extinction_coef       0.000162(7)
_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   1.067
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1146
_refine_ls_number_reflns         21634
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.067
_refine_ls_R_factor_all          0.1207
_refine_ls_R_factor_gt           0.0747
_refine_ls_shift/su_max          0.090
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0838P)^2^+383.3562P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1719
_refine_ls_wR_factor_ref         0.2154
_reflns_number_gt                14886
_reflns_number_total             21634
_reflns_threshold_expression     >2sigma(I)
_cod_duplicate_entry             7104806
_cod_data_source_file            b307276b.txt
_cod_data_source_block           1
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_cell_volume        4564.42(8)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7113444