Se2(B2O7): a new type of second-order NLO material.
Kong, Fang; Huang, Shu-Ping; Sun, Zhong-Ming; Mao, Jiang-Gao; Cheng, Wen-Dan; Journal of the American Chemical Society 128 (2006) 7750–7751; doi:10.1021/ja0620991

data_4101313
_publ_section_title
;
 Se2(B2O7): a new type of second-order NLO material.
;
_journal_issue                   24
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7750
_journal_page_last               7751
_journal_paper_doi               10.1021/ja0620991
_journal_volume                  128
_journal_year                    2006
_chemical_formula_sum            'B2 O7 Se2'
_chemical_formula_weight         291.54
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                   7.4815(6)
_cell_length_b                   7.8984(5)
_cell_length_c                   9.0478(7)
_cell_measurement_temperature    293(2)
_cell_volume                     534.65(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.954
_diffrn_measured_fraction_theta_max 0.954
_diffrn_measurement_device_type  'Siemens Smart CCD'
_diffrn_measurement_method       'narrow frame method'
_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  0.0452
_diffrn_reflns_av_sigmaI/netI    0.0627
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            3632
_diffrn_reflns_theta_full        29.68
_diffrn_reflns_theta_max         29.68
_diffrn_reflns_theta_min         3.42
_diffrn_standards_decay_%        <1.0%
_exptl_absorpt_coefficient_mu    13.811
_exptl_absorpt_correction_T_max  1.0
_exptl_absorpt_correction_T_min  0.348
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.622
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       brick
_exptl_crystal_F_000             536
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.980
_refine_diff_density_min         -0.996
_refine_diff_density_rms         0.278
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.02(3)
_refine_ls_extinction_coef       0.0366(18)
_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   1.158
_refine_ls_matrix_type           full
_refine_ls_number_parameters     101
_refine_ls_number_reflns         1420
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.158
_refine_ls_R_factor_all          0.0513
_refine_ls_R_factor_gt           0.0416
_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^)+(0.0139P)^2^+1.8368P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0708
_refine_ls_wR_factor_ref         0.0741
_reflns_number_gt                1269
_reflns_number_total             1420
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0620991si20060327_104326.cif
_cod_data_source_block           Se2B2O7
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               4101313