Refinement of the crystal structure of tetrasodium tetrasilicide, Na4Si4
Thorsten Goebel; Yurii Prots; Frank Haarmann; Zeitschrift für Kristallographie - New Crystal Structures 223 (2008) 187–; doi:

data_8102990
_publ_section_title
;
 Refinement of the crystal structure of tetrasodium tetrasilicide,
 Na4Si4
;
_journal_issue                   3
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              187
_journal_volume                  223
_journal_year                    2008
_chemical_formula_sum            'Na4 Si4'
_chemical_formula_weight         204.32
_chemical_name_systematic
;
tetrasodium tetrasilicide
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 118.90(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.1536(5)
_cell_length_b                   6.5452(5)
_cell_length_c                   11.1323(6)
_cell_measurement_temperature    293(2)
_cell_volume                     775.3(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.936
_diffrn_measured_fraction_theta_max 0.936
_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  0.012
_diffrn_reflns_av_sigmaI/netI    0.017
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            2975
_diffrn_reflns_theta_full        31.50
_diffrn_reflns_theta_max         31.50
_diffrn_reflns_theta_min         3.65
_exptl_absorpt_coefficient_mu    0.879
_exptl_crystal_colour            silver
_exptl_crystal_density_diffrn    1.751
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular shaped'
_exptl_crystal_F_000             400
_exptl_crystal_size_max          0.060
_exptl_crystal_size_mid          0.050
_exptl_crystal_size_min          0.045
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.363
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.149
_refine_ls_matrix_type           full
_refine_ls_number_parameters     37
_refine_ls_number_reflns         1204
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.149
_refine_ls_R_factor_all          0.030
_refine_ls_R_factor_gt           0.028
_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^)+(0.0262P)^2^+0.4775P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.063
_refine_ls_wR_factor_ref         0.064
_reflns_number_gt                1139
_reflns_number_total             1204
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            409953.cff
_cod_data_source_block           Na4Si4
_cod_depositor_comments
;

2024-04-15
Formula fixed to be consistent with given Z
                 miguel
;
_cod_original_formula_sum            'Na16 Si16'
_cod_original_formula_weight         817.28
_cod_original_cell_volume        775.27(8)
_cod_original_sg_symbol_H-M      C12/c1
_cod_database_code               8102990