β-Nb9VO25
Nasri, Rawia; Chérif, Saïda Fatma; Zid, Mohamed Faouzi; Driss, Ahmed; Acta Crystallographica Section E Structure Reports Online 70 (2014) i20–; doi:10.1107/S1600536814007831

data_2239348
_publ_section_title
;
 \b-Nb9VO25
;
_journal_coeditor_code           VN2081
_journal_issue                   5
_journal_name_full
'Acta Crystallographica Section E Structure Reports Online'
_journal_page_first              i20
_journal_paper_doi               10.1107/S1600536814007831
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'Nb9 V O25'
_chemical_formula_moiety         'Nb9 O25 V'
_chemical_formula_sum            'Nb9 O25 V'
_chemical_formula_weight         1287.13
_chemical_name_systematic
;
Nonaniobium vanadium pentacosaoxide
;
_space_group_IT_number           87
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4'
_symmetry_space_group_name_H-M   'I 4/m'
_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            2
_cell_length_a                   15.7726(9)
_cell_length_b                   15.7726(9)
_cell_length_c                   3.8399(6)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      15
_cell_measurement_theta_min      11
_cell_volume                     955.27(17)
_computing_cell_refinement
'CAD-4 EXPRESS (Duisenberg, 1992; Mac\'i\<cek & Yordanov, 1992)'
_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 & Putz, 1999)'
_computing_publication_material  'WinGX (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0442
_diffrn_reflns_av_sigmaI/netI    0.0784
_diffrn_reflns_limit_h_max       1
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       1
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       1
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            851
_diffrn_reflns_theta_full        26.93
_diffrn_reflns_theta_max         26.93
_diffrn_reflns_theta_min         2.58
_diffrn_standards_decay_%        1.1
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    5.775
_exptl_absorpt_correction_T_max  0.812
_exptl_absorpt_correction_T_min  0.695
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>, 1968)'
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    4.475
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.144
_exptl_crystal_size_mid          0.054
_exptl_crystal_size_min          0.036
_refine_diff_density_max         1.149
_refine_diff_density_min         -1.522
_refine_ls_extinction_coef       0.0050(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   0.991
_refine_ls_matrix_type           full
_refine_ls_number_parameters     56
_refine_ls_number_reflns         593
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.991
_refine_ls_R_factor_all          0.0826
_refine_ls_R_factor_gt           0.0344
_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^)+(0.0234P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0709
_refine_ls_wR_factor_ref         0.0856
_reflns_number_gt                363
_reflns_number_total             593
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            vn2081sup1.cf
_cod_data_source_block           I
_cod_database_code               2239348
_cod_database_fobs_code          2239348