Is it all in the hinge? A kryptoracemate and three of its alternative racemic polymorphs of an aminonitrile.
Laubenstein, R.; Şerb, M-D; Englert, U.; Raabe, G.; Braun, T.; Braun, B.; Chemical communications (Cambridge, England) 52 (2016) 1214–1217; doi:10.1039/c5cc08992a

data_7118359
_publ_section_title
;
 Is it all in the hinge? A kryptoracemate and three of its alternative
 racemic polymorphs of an aminonitrile.
;
_journal_issue                   6
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1214
_journal_page_last               1217
_journal_paper_doi               10.1039/c5cc08992a
_journal_volume                  52
_journal_year                    2016
_chemical_formula_sum            'C14 H7 F5 N2'
_chemical_formula_weight         298.22
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 21'
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2013
_audit_update_record
;
2015-07-22 deposited with the CCDC.
2015-11-18 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            16
_cell_length_a                   25.3241(16)
_cell_length_b                   6.5350(5)
_cell_length_c                   29.874(2)
_cell_measurement_temperature    100(2)
_cell_volume                     4943.9(6)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.998
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.1811
_diffrn_reflns_av_unetI/netI     0.1194
_diffrn_reflns_Laue_measured_fraction_full 0.980
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            44264
_diffrn_reflns_point_group_measured_fraction_full 0.980
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         66.787
_diffrn_reflns_theta_min         2.958
_exptl_absorpt_coefficient_mu    1.327
_exptl_crystal_density_diffrn    1.603
_exptl_crystal_F_000             2400
_exptl_crystal_size_max          0.150
_exptl_crystal_size_mid          0.020
_exptl_crystal_size_min          0.010
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_refine_diff_density_min         -0.294
_refine_diff_density_rms         0.061
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.7(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.014
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     787
_refine_ls_number_reflns         8260
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.013
_refine_ls_R_factor_all          0.1362
_refine_ls_R_factor_gt           0.0607
_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^)+(0.0536P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1090
_refine_ls_wR_factor_ref         0.1381
_reflns_Friedel_coverage         0.959
_reflns_Friedel_fraction_full    0.980
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                4789
_reflns_number_total             8260
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c5cc08992a2.cif
_cod_data_source_block           rac1b_250615
_cod_database_code               7118359
_shelx_estimated_absorpt_t_min   0.826
_shelx_estimated_absorpt_t_max   0.987
_shelxl_version_number           2013-4
_shelx_res_checksum              8880
_shelx_hkl_checksum              50686