Nature of E<sub>2</sub>X<sub>2</sub> σ(4c-6e) of the X—E-E—X type at naphthalene 1,8-positions and model, elucidated by X-ray crystallographic analysis and QC calculations with the QTAIM approach.
Tsubomoto, Yutaka; Hayashi, Satoko; Nakanishi, Waro; Sasamori, Takahiro; Tokitoh, Norihiro; Acta crystallographica Section B, Structural science, crystal engineering and materials 73 (2017) 265–275; doi:10.1107/S205252061700364X

data_2311702
_publ_section_title
;
 Nature of E<sub>2</sub>X<sub>2</sub> \s(4c-6e) of the X---E-E---X type at
 naphthalene 1,8-positions and model, elucidated by X-ray crystallographic
 analysis and QC calculations with the QTAIM approach.
;
_journal_issue                   'Pt 2'
_journal_name_full
'Acta crystallographica Section B, Structural science, crystal engineering and materials'
_journal_page_first              265
_journal_page_last               275
_journal_paper_doi               10.1107/S205252061700364X
_journal_volume                  73
_journal_year                    2017
_chemical_formula_moiety         'C20 H12 Cl2 Se2'
_chemical_formula_sum            'C20 H12 Cl2 Se2'
_chemical_formula_weight         481.12
_chemical_name_common            Compound_3
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_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                90.00
_cell_formula_units_Z            8
_cell_length_a                   7.89330(10)
_cell_length_b                   29.1713(4)
_cell_length_c                   14.4594(2)
_cell_measurement_reflns_used    6129
_cell_measurement_temperature    103(2)
_cell_measurement_theta_max      25.50
_cell_measurement_theta_min      2.09
_cell_volume                     3329.39(8)
_computing_cell_refinement       HKL2000
_computing_data_collection       CrystalClear
_computing_data_reduction        HKL2000
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR-97
_diffrn_ambient_temperature      103(2)
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Rigaku Mercury'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0484
_diffrn_reflns_av_sigmaI/netI    0.0374
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -35
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            22104
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.09
_exptl_absorpt_coefficient_mu    4.761
_exptl_absorpt_correction_T_max  0.7967
_exptl_absorpt_correction_T_min  0.2866
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.920
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1872
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.406
_refine_diff_density_min         -0.589
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.122(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     433
_refine_ls_number_reflns         6129
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0264
_refine_ls_R_factor_gt           0.0243
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0339P)^2^+0.0876P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0592
_refine_ls_wR_factor_ref         0.0600
_reflns_number_gt                5798
_reflns_number_total             6129
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            xm5002sup1.cif
_cod_data_source_block           Compound_3
_cod_database_code               2311702