Fe^II^~3~Fe^III^~4~(AsO~4~)~6~, the first arsenate adopting the Fe~7~(PO~4~)~6~ structure type
Weil, Matthias; Acta Crystallographica, Section E 60 (2004) i139–i141; doi:10.1107/S1600536804026182

data_2204429
_publ_section_title
;
Fe^II^~3~Fe^III^~4~(AsO~4~)~6~, the first arsenate adopting the
Fe~7~(PO~4~)~6~ structure type
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica, Section E'
_journal_page_first              i139
_journal_page_last               i141
_journal_paper_doi               10.1107/S1600536804026182
_journal_volume                  60
_journal_year                    2004
_chemical_formula_iupac          'Fe7 (As O4)6'
_chemical_formula_structural     'Fe7 (As O4)6'
_chemical_formula_sum            'As6 Fe7 O24'
_chemical_formula_weight         1224.47
_chemical_name_common            'Iron (II, III) arsenate'
_chemical_name_systematic
;
Triiron(II) tetrairon (III) hexakisorthoarsenate(V)
;
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   none
_atom_sites_solution_primary     isomor
_audit_creation_method           SHELXL-97
_cell_angle_alpha                104.843(7)
_cell_angle_beta                 107.936(6)
_cell_angle_gamma                101.842(9)
_cell_formula_units_Z            1
_cell_length_a                   6.5738(6)
_cell_length_b                   8.0973(9)
_cell_length_c                   9.6190(6)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      17.918
_cell_measurement_theta_min      13.665
_cell_volume                     447.85(8)
_computing_cell_refinement       'CAD-4 Software'
_computing_data_collection       'CAD-4 Software (Enraf-Nonius, 1989)'
_computing_data_reduction        'HELENA implemented in PLATON (Spek, 2002)'
_computing_molecular_graphics    'ATOMS (Dowty, 2000)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution
'from the coordinates of Gorbunov et al. (1980)'
_database_code_amcsd             0010440
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_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  0.0240
_diffrn_reflns_av_sigmaI/netI    0.0274
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            7836
_diffrn_reflns_theta_full        34.96
_diffrn_reflns_theta_max         34.96
_diffrn_reflns_theta_min         2.37
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  300
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    16.642
_exptl_absorpt_correction_T_max  0.2659
_exptl_absorpt_correction_T_min  0.0215
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   '(HABITUS; Herrendorf, 1993-1997)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    4.540
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             572
_exptl_crystal_size_max          0.396
_exptl_crystal_size_mid          0.288
_exptl_crystal_size_min          0.144
_refine_diff_density_max         1.045
_refine_diff_density_min         -1.118
_refine_ls_extinction_coef       0.0387(8)
_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   1.158
_refine_ls_matrix_type           full
_refine_ls_number_parameters     170
_refine_ls_number_reflns         3918
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.158
_refine_ls_R_factor_all          0.0239
_refine_ls_R_factor_gt           0.0205
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0213P)^2^+0.3318P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0475
_refine_ls_wR_factor_ref         0.0483
_reflns_number_gt                3589
_reflns_number_total             3918
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            br6166.cif
_cod_database_code               2204429
_amcsd_formula_title             Fe7(AsO4)6