The novel arsenate Na~4~Co~7{-~<i>x</i>}Al~2/3<i>x~</i>(AsO~4~)~6~ (<i>x</i> = 1.37): crystal structure, charge-distribution and bond-valence-sum investigations
Marzouki, Riadh; Guesmi, Abderrahmen; Driss, Ahmed; Acta Crystallographica Section C 66 (2010) i95–i98; doi:10.1107/S0108270110037376

data_2017866
_publ_section_title
;
 The novel arsenate Na~4~Co~7{-~<i>x</i>}Al~2/3<i>x~</i>(AsO~4~)~6~
 (<i>x</i> = 1.37): crystal structure, charge-distribution and
 bond-valence-sum investigations
;
_journal_coeditor_code           SQ3262
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i95
_journal_page_last               i98
_journal_paper_doi               10.1107/S0108270110037376
_journal_volume                  66
_journal_year                    2010
_chemical_formula_iupac          'Na4 Co5.63 Al0.91 (As O4)6'
_chemical_formula_moiety         'Al0.91 As6 Co5.63 Na4 O24'
_chemical_formula_sum            'Al0.91 As6 Co5.63 Na4 O24'
_chemical_formula_weight         1281.94
_chemical_name_systematic
;
tetrasodium cobalt aluminium hexaarsenate
;
_space_group_IT_number           12
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2y'
_symmetry_space_group_name_H-M   'C 1 2/m 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 105.51(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.744(4)
_cell_length_b                   14.847(3)
_cell_length_c                   6.722(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14.53
_cell_measurement_theta_min      11.01
_cell_volume                     1033.2(7)
_computing_cell_refinement       'CAD-4 EXPRESS (Enraf--Nonius, 1995)'
_computing_data_collection       'CAD-4 EXPRESS (Enraf--Nonius, 1995)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1998)'
_computing_publication_material  'WinGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_diffrn_measurement_device_type  'Enraf--Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_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  0.0275
_diffrn_reflns_av_sigmaI/netI    0.0301
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       2
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            1584
_diffrn_reflns_theta_full        26.96
_diffrn_reflns_theta_max         26.96
_diffrn_reflns_theta_min         2.40
_diffrn_standards_decay_%        1
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    14.198
_exptl_absorpt_correction_T_max  0.0435
_exptl_absorpt_correction_T_min  0.0400
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details
;
(North <i>et al.</i>, 1968)
;
_exptl_crystal_colour            pink
_exptl_crystal_density_diffrn    4.121
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelipiped
_exptl_crystal_F_000             1196
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.899
_refine_diff_density_min         -0.909
_refine_ls_extinction_coef       0.00110(14)
_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   1.130
_refine_ls_matrix_type           full
_refine_ls_number_parameters     117
_refine_ls_number_reflns         1157
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.129
_refine_ls_R_factor_all          0.0312
_refine_ls_R_factor_gt           0.0261
_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^)+(0.0275P)^2^+8.3215P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0656
_refine_ls_wR_factor_ref         0.0678
_reflns_number_gt                1042
_reflns_number_total             1157
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sq3262.cif
_cod_data_source_block           I
_cod_original_cell_volume        1033.2(6)
_cod_original_sg_symbol_H-M      'C 2/m'
_cod_database_code               2017866
_cod_database_fobs_code          2017866