The aluminoarsenate K~1.8~Sr~0.6~Al~3~(AsO~4~)~4~
Haj Abdallah, Anissa; Haddad, Amor; Acta Crystallographica Section E 68 (2012) i29–; doi:10.1107/S1600536812014304

data_2234515
_publ_section_title
;
 The aluminoarsenate K~1.8~Sr~0.6~Al~3~(AsO~4~)~4~
;
_journal_coeditor_code           BR2195
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i29
_journal_paper_doi               10.1107/S1600536812014304
_journal_volume                  68
_journal_year                    2012
_chemical_formula_iupac          'K1.8 Sr0.6 Al3 (As O4)4'
_chemical_formula_structural     'K1.8 Sr0.6 Al3 (AsO4)4'
_chemical_formula_sum            'Al3 As4 K1.8 O16 Sr0.6'
_chemical_formula_weight         759.57
_chemical_name_systematic
;
potassium strontium trialuminium tetraarsenate
;
_space_group_IT_number           64
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-C 2ac 2'
_symmetry_space_group_name_H-M   'C m c a'
_atom_sites_solution_primary     vecmap
_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            4
_cell_length_a                   10.567(3)
_cell_length_b                   20.531(4)
_cell_length_c                   6.3880(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27
_cell_measurement_theta_min      2.2
_cell_volume                     1385.9(5)
_computing_cell_refinement       'CAD-4 EXPRESS (Enraf--Nonius, 1994)'
_computing_data_collection       'CAD-4 EXPRESS (Enraf--Nonius, 1994)'
_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 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0241
_diffrn_reflns_av_sigmaI/netI    0.0300
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            1510
_diffrn_reflns_theta_full        26.97
_diffrn_reflns_theta_max         26.97
_diffrn_reflns_theta_min         3.76
_diffrn_standards_decay_%        0.4
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    12.671
_exptl_absorpt_correction_T_max  0.2915
_exptl_absorpt_correction_T_min  0.0881
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>, 1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.641
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelipedic
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.14
_refine_diff_density_max         1.679
_refine_diff_density_min         -1.450
_refine_ls_extinction_coef       0.0006(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.089
_refine_ls_matrix_type           full
_refine_ls_number_parameters     88
_refine_ls_number_reflns         796
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.089
_refine_ls_R_factor_all          0.0444
_refine_ls_R_factor_gt           0.0387
_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^)+(0.0826P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1070
_refine_ls_wR_factor_ref         0.1118
_reflns_number_gt                704
_reflns_number_total             796
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            br2195.cif
_cod_data_source_block           I
_cod_original_sg_symbol_Hall     '-C 2bc 2'
_cod_original_sg_symbol_H-M      'C m c e'
_cod_database_code               2234515
_cod_database_fobs_code          2234515