A helical structure with <i>Z</i>' = 10
Hao, Xiang; Chen, Jing; Cammers, Arthur; Parkin, Sean; Brock, Carolyn Pratt; Acta Crystallographica Section B 61 (2005) 218–226; doi:10.1107/S0108768105004076

data_2100139
_publ_section_title
;
 A helical structure with <i>Z</i>' = 10
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              218
_journal_page_last               226
_journal_paper_doi               10.1107/S0108768105004076
_journal_volume                  61
_journal_year                    2005
_chemical_formula_moiety         'C8 H16 N4'
_chemical_formula_sum            'C8 H16 N4'
_chemical_formula_weight         168.25
_chemical_melting_point          410
_chemical_name_systematic
;
N''-cyano-N,N-diisopropylguanidine
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 102.940(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            40
_cell_length_a                   20.247(2)
_cell_length_b                   18.212(2)
_cell_length_c                   27.665(3)
_cell_measurement_reflns_used    40263
_cell_measurement_temperature    90.0(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      1.00
_cell_volume                     9942.1(19)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics
;
XP in Siemens SHELXTL (Sheldrick, 1994);
Mercury (Bruno et al., 2002)
;
_computing_publication_material
;
SHELXL-97 (Sheldrick, 1997) and local procedures
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997b)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997a)'
_diffrn_ambient_temperature      90(2)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       '1.2\% \w scans at fixed \c = 55\%'
_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  0.0734
_diffrn_reflns_av_sigmaI/netI    0.0667
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            60120
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.35
_diffrn_standards_decay_%        <1.
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.073
_exptl_absorpt_correction_T_max  0.9856
_exptl_absorpt_correction_T_min  0.9716
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO-SMN (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.124
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thick plate'
_exptl_crystal_F_000             3680
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.292
_refine_diff_density_min         -0.208
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.996
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1206
_refine_ls_number_reflns         17510
_refine_ls_number_restraints     248
_refine_ls_restrained_S_all      0.992
_refine_ls_R_factor_all          0.1010
_refine_ls_R_factor_gt           0.0499
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0683P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1112
_refine_ls_wR_factor_ref         0.1314
_reflns_number_gt                10748
_reflns_number_total             17510
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bm5021.cif
_cod_data_source_block           k03124
_cod_original_cell_volume        9942.3(19)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2100139