Trigonal Planar [HgSe3](4-) Unit: A New Kind of Basic Functional Group in IR Nonlinear Optical Materials with Large Susceptibility and Physicochemical Stability.
Li, Chao; Yin, Wenlong; Gong, Pifu; Li, Xiaoshuang; Zhou, Molin; Mar, Arthur; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng; Chen, Chuangtian; Journal of the American Chemical Society 138 (2016) 6135–6138; doi:10.1021/jacs.6b03107

data_4125072
_publ_section_title
;
 Trigonal Planar [HgSe3](4-) Unit: A New Kind of Basic Functional Group in
 IR Nonlinear Optical Materials with Large Susceptibility and
 Physicochemical Stability.
;
_journal_issue                   19
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6135
_journal_page_last               6138
_journal_paper_doi               10.1021/jacs.6b03107
_journal_volume                  138
_journal_year                    2016
_chemical_formula_sum            'Ba Hg Se2'
_chemical_formula_weight         495.85
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           26
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2'
_symmetry_space_group_name_H-M   'P m c 21'
_atom_sites_solution_hydrogens   none
_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            4
_cell_length_a                   4.3580(9)
_cell_length_b                   14.881(3)
_cell_length_c                   7.5900(15)
_cell_measurement_reflns_used    128
_cell_measurement_temperature    153(2)
_cell_measurement_theta_max      31.4507
_cell_measurement_theta_min      2.6836
_cell_volume                     492.22(17)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      153(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  CCD
_diffrn_measurement_method       dtprofit.ref
_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  0.0993
_diffrn_reflns_av_sigmaI/netI    0.1425
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            4790
_diffrn_reflns_theta_full        31.52
_diffrn_reflns_theta_max         31.52
_diffrn_reflns_theta_min         2.74
_exptl_absorpt_coefficient_mu    53.692
_exptl_absorpt_correction_T_max  0.16
_exptl_absorpt_correction_T_min  0.12
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'face indexed'
_exptl_crystal_colour            Black
_exptl_crystal_density_diffrn    6.691
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Chip
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.1800
_exptl_crystal_size_mid          0.1600
_exptl_crystal_size_min          0.1100
_refine_diff_density_max         5.796
_refine_diff_density_min         -5.225
_refine_diff_density_rms         0.993
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.03(2)
_refine_ls_extinction_coef       0.0012(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.990
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     50
_refine_ls_number_reflns         1698
_refine_ls_number_restraints     25
_refine_ls_restrained_S_all      0.989
_refine_ls_R_factor_all          0.0883
_refine_ls_R_factor_gt           0.0679
_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^)+(0.0500P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1330
_refine_ls_wR_factor_ref         0.1445
_reflns_number_gt                1189
_reflns_number_total             1698
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja6b03107_si_006.cif
_cod_data_source_block           a
_cod_depositor_comments          'Adding full bibliography for 4125072.cif.'
_cod_original_sg_symbol_H-M      Pmc21
_cod_database_code               4125072