Validation of experimental charge-density refinement strategies: when do we overfit?
Krause, Lennard; Niepötter, Benedikt; Schürmann, Christian J.; Stalke, Dietmar; Herbst-Irmer, Regine; IUCrJ 4 (2017) –; doi:10.1107/S2052252517005103

data_1546113
_publ_section_title
;
 Validation of experimental charge-density refinement strategies: when do
 we overfit?
;
_journal_issue                   4
_journal_name_full               IUCrJ
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2052252517005103
_journal_volume                  4
_journal_year                    2017
_chemical_formula_moiety         'C24 H18 B F10 N'
_chemical_formula_sum            'C24 H18 B F10 N'
_chemical_formula_weight         521.20
_space_group_crystal_system      tetragonal
_space_group_IT_number           114
_space_group_name_Hall           'P -4 2n'
_space_group_name_H-M_alt        'P -4 21 c'
_symmetry_space_group_name_Hall  'P -4 2n'
_symmetry_space_group_name_H-M   'P -4 21 c'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2016/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   22.206(3)
_cell_length_b                   22.206(3)
_cell_length_c                   8.692(2)
_cell_measurement_reflns_used    8098
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      49.131
_cell_measurement_theta_min      2.5935
_cell_volume                     4286.1(13)
_computing_cell_refinement       'SAINT V8.30C'
_computing_data_collection       'APEX2 v2012.2'
_computing_data_reduction        'SAINT V8.30C'
_computing_molecular_graphics    'XP Version 5.1'
_computing_publication_material  'XP Version 5.1'
_computing_structure_refinement  'SHELXL-2016/6 (Sheldrick, 2016)'
_computing_structure_solution
'SHELXT(G.M.Sheldrick,Acta Cryst.(2015)A71,3-8)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker Smart APEX II Ultra'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0412
_diffrn_reflns_av_unetI/netI     0.0133
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       47
_diffrn_reflns_limit_h_min       -47
_diffrn_reflns_limit_k_max       46
_diffrn_reflns_limit_k_min       -46
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            404587
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         49.187
_diffrn_reflns_theta_min         1.297
_diffrn_source                   'BRUKER Rotating Anode'
_exptl_absorpt_coefficient_mu    0.155
_exptl_absorpt_correction_T_max  0.9705
_exptl_absorpt_correction_T_min  0.9279
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2015/1'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.615
_exptl_crystal_description       block
_exptl_crystal_F_000             2112
_exptl_crystal_size_max          0.100
_exptl_crystal_size_mid          0.090
_exptl_crystal_size_min          0.090
_refine_diff_density_max         0.508
_refine_diff_density_min         -0.252
_refine_diff_density_rms         0.060
_refine_ls_abs_structure_details
;
 Flack x determined using 8376 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.03(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.124
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     327
_refine_ls_number_reflns         21597
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.124
_refine_ls_R_factor_all          0.0371
_refine_ls_R_factor_gt           0.0298
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0489P)^2^+0.0917P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0792
_refine_ls_wR_factor_ref         0.0835
_reflns_Friedel_coverage         0.864
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.994
_reflns_number_gt                19346
_reflns_number_total             21597
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            lc5072.cif
_cod_data_source_block           1_shelx
_cod_original_cell_volume        4286.1(15)
_cod_database_code               1546113
_shelx_shelxl_version_number     2016/6
_shelx_res_checksum              1601
_shelx_hkl_checksum              64322