Ca1-xNa2xAl2B2O7: A Structure with Tunable Density of Na+Vacancies
He, Meng; Okudera, Hiroki; Simon, Arndt; Inorganic Chemistry 44 (2005) 4421–4426; doi:10.1021/ic0500863

data_4331484
_publ_section_title
;
 Ca1-xNa2xAl2B2O7:&#x00A0; A Structure with Tunable Density of
 Na+Vacancies
;
_journal_issue                   12
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              4421
_journal_page_last               4426
_journal_paper_doi               10.1021/ic0500863
_journal_volume                  44
_journal_year                    2005
_chemical_formula_sum            'Al2 B2 Ca0.69 Na0.64 O7'
_chemical_formula_weight         230.02
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           176
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_Hall  '-P 6c'
_symmetry_space_group_name_H-M   'P 63/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                120.00
_cell_formula_units_Z            2
_cell_length_a                   4.8238(5)
_cell_length_b                   4.8238(5)
_cell_length_c                   15.472(3)
_cell_measurement_temperature    293(2)
_cell_volume                     311.79(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'image plate'
_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  0.0349
_diffrn_reflns_av_sigmaI/netI    0.0164
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            3735
_diffrn_reflns_theta_full        31.89
_diffrn_reflns_theta_max         31.89
_diffrn_reflns_theta_min         2.63
_exptl_absorpt_coefficient_mu    1.069
_exptl_absorpt_correction_T_max  0.9683
_exptl_absorpt_correction_T_min  0.8971
_exptl_absorpt_correction_type   numerical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    2.450
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate-like
_exptl_crystal_F_000             226
_exptl_crystal_size_max          0.120
_exptl_crystal_size_mid          0.080
_exptl_crystal_size_min          0.024
_refine_diff_density_max         0.434
_refine_diff_density_min         -0.508
_refine_diff_density_rms         0.104
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.095
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     29
_refine_ls_number_reflns         375
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.095
_refine_ls_R_factor_all          0.0407
_refine_ls_R_factor_gt           0.0345
_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^)+(0.0555P)^2^+0.1724P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0839
_refine_ls_wR_factor_ref         0.0867
_reflns_number_gt                347
_reflns_number_total             375
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic0500863sup1.cif
_cod_data_source_block           x-0.32
_cod_original_cell_volume        311.79(7)
_cod_database_code               4331484