Synthesis and Characterization of K38Nb7As24 and Cs9Nb2As6: The First Mixed-Valence Transition-Metal Zintl Phases
Franck Gascoin; Slavi C. Sevov; Inorganic Chemistry 41 (2002) 5920–5924; doi:10.1021/ic020250b

data_4318759
_publ_section_title
;
 Synthesis and Characterization of K38Nb7As24 and Cs9Nb2As6: The First
 Mixed-Valence Transition-Metal Zintl Phases
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              5920
_journal_page_last               5924
_journal_paper_doi               10.1021/ic020250b
_journal_volume                  41
_journal_year                    2002
_chemical_formula_moiety         K38Nb7As24
_chemical_formula_sum            'As24 K38 Nb7'
_chemical_formula_weight         3934.25
_chemical_name_common            K38Nb7As24
_chemical_name_systematic
;
   ?
;
_space_group_IT_number           63
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-C 2c 2'
_symmetry_space_group_name_H-M   'C m c m'
_atom_sites_solution_hydrogens   geom
_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            4
_cell_length_a                   10.4974(7)
_cell_length_b                   23.915(2)
_cell_length_c                   36.047(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19.743
_cell_measurement_theta_min      11.698
_cell_volume                     9049.4(11)
_computing_cell_refinement       CAD4_(Enraf-Nonius,_1977)
_computing_data_collection       CAD4_(Enraf-Nonius,_1977)
_computing_data_reduction        SDS_Package_(Enraf-Nonius,_1985)
_computing_molecular_graphics    'SHELXTL (Siemens, 1994)'
_computing_publication_material  'SHELXTL (Siemens, 1994)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_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_Cad4
_diffrn_measurement_method       omega-2theta
_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  0.0808
_diffrn_reflns_av_sigmaI/netI    0.0951
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       28
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       42
_diffrn_reflns_limit_l_min       -42
_diffrn_reflns_number            8439
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.04
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    11.329
_exptl_absorpt_correction_T_max  0.31929
_exptl_absorpt_correction_T_min  0.19819
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   'average of 4 psi-scans reflections'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    2.888
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             7204
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.08
_refine_diff_density_max         2.712
_refine_diff_density_min         -1.207
_refine_diff_density_rms         0.298
_refine_ls_extinction_coef       0.000004(8)
_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   1.008
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     194
_refine_ls_number_reflns         4295
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.1118
_refine_ls_R_factor_gt           0.0598
_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^)+(0.0825P)^2^+6.2925P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1340
_refine_ls_wR_factor_ref         0.1570
_reflns_number_gt                2772
_reflns_number_total             4295
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic020250b_1.cif
_cod_data_source_block           k38nb7as24
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' tag value 'psi-scans' was replaced
with 'psi-scan' value.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        9049.2(11)
_cod_database_code               4318759