Dipotassium heptafluorotantalate(V), β-K~2~TaF~7~, at 509 K
Vratislav Langer; Łubomír Smrčok; Miroslav Boča; Acta Crystallographica Section E 62 (2006) i91–i93; doi:10.1107/S1600536806009147

data_2208744
_publ_section_title
;
 Dipotassium heptafluorotantalate(V), \b-K~2~TaF~7~, at 509 K
;
_journal_coeditor_code           WM2004
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i91
_journal_page_last               i93
_journal_paper_doi               10.1107/S1600536806009147
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'K2 Ta F7'
_chemical_formula_structural     'K2 Ta F7'
_chemical_formula_sum            'F7 K2 Ta'
_chemical_formula_weight         392.15
_chemical_name_systematic        'Dipotassium heptafluorotantalate(V)'
_space_group_IT_number           62
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2n'
_symmetry_space_group_name_H-M   'P n m a'
_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                   9.8155(15)
_cell_length_b                   5.8212(8)
_cell_length_c                   12.0041(18)
_cell_measurement_reflns_used    801
_cell_measurement_temperature    509(2)
_cell_measurement_theta_max      28.32
_cell_measurement_theta_min      2.68
_cell_volume                     685.89(17)
_computing_cell_refinement       'SAINT (Siemens, 1995)'
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'DIAMOND (Brandenburg, 2000)'
_computing_publication_material  'PLATON (Spek, 2003)'
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Bruker, 2001)'
_diffrn_ambient_temperature      509(2)
_diffrn_measured_fraction_theta_full 0.873
_diffrn_measured_fraction_theta_max 0.825
_diffrn_measurement_device_type  'Siemens SMART CCD'
_diffrn_measurement_method       \w
_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  0.0617
_diffrn_reflns_av_sigmaI/netI    0.0643
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -4
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            2231
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.32
_diffrn_reflns_theta_min         2.68
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    17.298
_exptl_absorpt_correction_T_max  0.0854
_exptl_absorpt_correction_T_min  0.0248
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2002)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.798
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.82
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.28
_refine_diff_density_max         1.478
_refine_diff_density_min         -2.419
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_matrix_type           full
_refine_ls_number_parameters     34
_refine_ls_number_reflns         771
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.1218
_refine_ls_R_factor_gt           0.0711
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1230P)^2^+12.4367P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1871
_refine_ls_wR_factor_ref         0.2204
_reflns_number_gt                443
_reflns_number_total             771
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            wm2004.cif
_cod_data_source_block           I
_cod_database_code               2208744
_cod_database_fobs_code          2208744