Synchrotron X-ray and <i>ab initio</i> studies of β-Si~3~N~4~
du Boulay, D.; Ishizawa, N.; Atake, T.; Streltsov, V.; Furuya, K.; Munakata, F.; Acta Crystallographica Section B 60 (2004) 388–405; doi:10.1107/S010876810401393X

data_2102551
_publ_section_title
;
 Synchrotron X-ray and <i>ab initio</i> studies of \b-Si~3~N~4~
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              388
_journal_page_last               405
_journal_paper_doi               10.1107/S010876810401393X
_journal_volume                  60
_journal_year                    2004
_chemical_formula_moiety         'N4 Si3'
_chemical_formula_sum            'N4 Si3'
_chemical_formula_weight         140.31
_chemical_name_common            '\b silicon nitride'
_space_group_crystal_system      hexagonal
_space_group_IT_number           173
_space_group_name_Hall           'P 6c'
_space_group_name_H-M_alt        'P 63'
_cell_angle_alpha                90.00000
_cell_angle_beta                 90.00000
_cell_angle_gamma                120.0000
_cell_formula_units_Z            1.5
_cell_length_a                   7.60440(10)
_cell_length_b                   7.60440(10)
_cell_length_c                   2.90630(10)
_cell_measurement_reflns_used    21
_cell_measurement_temperature    295
_cell_measurement_theta_max      63.90
_cell_measurement_theta_min      45.75
_cell_volume                     145.546(6)
_computing_cell_refinement       'xtal3.7 LATCON'
_computing_data_collection       'Diff14A, Vaalsta & Hester 1997'
_computing_data_reduction        'xtal DIFDAT SORTRF ABSORB ADDREF'
_computing_molecular_graphics    xtal
_computing_publication_material  'xtal BONDLA CIFIO'
_computing_structure_refinement  'xtal CRYLSQ'
_computing_structure_solution    'already known structure'
_diffrn_ambient_temperature      295
_diffrn_measured_fraction_theta_full 1.0
_diffrn_measurement_device_type  PF-BL14A_Rigaku_4circle
_diffrn_measurement_method       %w/2%q
_diffrn_radiation_monochromator  'Double Si '
_diffrn_radiation_source         Synchrotron
_diffrn_radiation_type           'syn x'
_diffrn_radiation_wavelength     .75022
_diffrn_reflns_av_R_equivalents  .025
_diffrn_reflns_av_sigmaI/netI    .012
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            8577
_diffrn_reflns_reduction_process 'equatorial monochr Lp'
_diffrn_reflns_theta_full        60
_diffrn_reflns_theta_max         64.99
_diffrn_reflns_theta_min         3.27
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 100
_diffrn_standards_number         6
_exptl_absorpt_coefficient_mu    1.533
_exptl_absorpt_correction_T_max  .9395
_exptl_absorpt_correction_T_min  .9390
_exptl_absorpt_correction_type   sphere
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.202
_exptl_crystal_description       spheroid
_exptl_crystal_F_000             140
_exptl_crystal_size_max          .075
_exptl_crystal_size_mid          .075
_exptl_crystal_size_min          .075
_exptl_crystal_size_rad          .0375
_refine_diff_density_max         .528
_refine_diff_density_min         -.48
_refine_ls_abs_structure_details 'see text'
_refine_ls_extinction_coef       21E2(4)
_refine_ls_extinction_expression 'Eq22 p292 "Cryst. Comp." Munksgaard 1970'
_refine_ls_extinction_method     Zachariasen
_refine_ls_goodness_of_fit_all   1.8771
_refine_ls_goodness_of_fit_ref   1.8771
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     22
_refine_ls_number_reflns         796
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          .0184
_refine_ls_R_factor_gt           .0184
_refine_ls_shift/su_max          .001
_refine_ls_shift/su_mean         .00015
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_all         .0135
_refine_ls_wR_factor_ref         .0135
_reflns_number_gt                792
_reflns_number_total             800
_reflns_threshold_expression     'F    >  .00 sig(F   )'
_cod_data_source_file            av5009.cif
_cod_original_sg_symbol_Hall     p_6c
_cod_original_sg_symbol_H-M      P_63
_cod_database_code               2102551