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_2311703
_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 Br2 Se2'
_chemical_formula_sum            'C20 H12 Br2 Se2'
_chemical_formula_weight         570.04
_chemical_name_common            Compound_4
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90.9410(10)
_cell_angle_beta                 101.8880(10)
_cell_angle_gamma                111.0930(10)
_cell_formula_units_Z            2
_cell_length_a                   7.83940(10)
_cell_length_b                   8.0986(2)
_cell_length_c                   15.0650(4)
_cell_measurement_reflns_used    19136
_cell_measurement_temperature    103(2)
_cell_measurement_theta_max      27.103
_cell_measurement_theta_min      2.860
_cell_volume                     868.92(3)
_computing_cell_refinement       HKL2000
_computing_data_collection       CrystalClear
_computing_data_reduction        HKL2000
_computing_molecular_graphics    'Yadokari-XG 2011 (Wakita Nemoto et al., 2011)'
_computing_publication_material  'Yadokari-XG 2011 (Wakita,Nemoto et al., 2011)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXT-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      103(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Rigaku VariMax Saturn'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0353
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            19136
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.103
_diffrn_reflns_theta_min         2.860
_exptl_absorpt_coefficient_mu    8.852
_exptl_absorpt_correction_T_max  0.915
_exptl_absorpt_correction_T_min  0.734
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 MULABS - Empirical Correction for Absorption Anisotropy.
 Blessing, R. H., Acta Cryst., A51, 33-38 (1995).
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    2.179
_exptl_crystal_description       platelet
_exptl_crystal_F_000             540
_exptl_crystal_size_max          0.040
_exptl_crystal_size_mid          0.030
_exptl_crystal_size_min          0.010
_refine_diff_density_max         1.684
_refine_diff_density_min         -1.276
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.198
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         3813
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.198
_refine_ls_R_factor_all          0.0432
_refine_ls_R_factor_gt           0.0391
_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^)+(0.0128P)^2^+4.9343P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0788
_refine_ls_wR_factor_ref         0.0805
_reflns_number_gt                3566
_reflns_number_total             3813
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            xm5002sup1.cif
_cod_data_source_block           Compound_4
_cod_database_code               2311703
_shelx_estimated_absorpt_t_min   0.718
_shelx_estimated_absorpt_t_max   0.917
_shelx_hkl_checksum              51631
_shelx_res_checksum              28639