Na~3~Cr~2~(AsO~4~)~3~: trisodium dichromium(III) triarsenate
Bouzemi, Besma; Boughzala, Habib; Jouini, Tahar; Acta Crystallographica, Section E: Structure Reports Online 58 (2002) i117–i118; doi:10.1107/s1600536802019128

data_2201252
_publ_section_title
;
 Na~3~Cr~2~(AsO~4~)~3~: trisodium dichromium(III) triarsenate
;
_journal_coden_ASTM              ACSEBH
_journal_issue                   12
_journal_name_full
;
 Acta Crystallographica, Section E: Structure Reports Online
;
_journal_page_first              i117
_journal_page_last               i118
_journal_paper_doi               10.1107/s1600536802019128
_journal_volume                  58
_journal_year                    2002
_chemical_formula_iupac          'Na3 Cr2 (As O4)3'
_chemical_formula_structural     'Na3 Cr2 (As O4)3'
_chemical_formula_sum            'As3 Cr2 Na3 O12'
_chemical_formula_weight         589.73
_chemical_name_systematic
;
 trisodium dichrome (III) triarsenate
;
_space_group_IT_number           230
_symmetry_cell_setting           cubic
_symmetry_space_group_name_Hall  '-I 4bd 2c 3'
_symmetry_space_group_name_H-M   'I a -3 d'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   12.188(2)
_cell_length_b                   12.188(2)
_cell_length_c                   12.188(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14
_cell_measurement_theta_min      10
_cell_volume                     1810.5(5)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection
'CAD-4 EXPRESS (Duisenberg, 1992; Mac\'i\<cek & Yordanov, 1992)'
_computing_data_reduction        'XCAD4(Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1998)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_database_code_amcsd             0010392
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.964
_diffrn_measured_fraction_theta_max 0.969
_diffrn_measurement_device_type  'Enarf-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  0.0208
_diffrn_reflns_av_sigmaI/netI    0.0153
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            735
_diffrn_reflns_theta_full        29.88
_diffrn_reflns_theta_max         29.88
_diffrn_reflns_theta_min         4.10
_diffrn_standards_decay_%        0.98
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    13.502
_exptl_absorpt_correction_T_max  0.5081
_exptl_absorpt_correction_T_min  0.4060
_exptl_absorpt_correction_type   '\y scan'
_exptl_absorpt_process_details   '(North et al., 1968)'
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    4.327
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       polyhedral
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.333
_refine_diff_density_min         -0.401
_refine_ls_extinction_coef       0.00326(17)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.136
_refine_ls_matrix_type           full
_refine_ls_number_parameters     18
_refine_ls_number_reflns         216
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.136
_refine_ls_R_factor_all          0.0236
_refine_ls_R_factor_gt           0.0191
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0156P)^2^+7.0122P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0380
_refine_ls_wR_factor_ref         0.0391
_reflns_number_gt                194
_reflns_number_total             216
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            br6064.cif
_cod_data_source_block           I
_cod_original_cell_volume        1810.6(5)
_cod_database_code               2201252
_cod_database_fobs_code          2201252
_amcsd_formula_title             Na3Cr2(AsO4)3