C18H20N4O2
Jones, Ray C.F.; Horton, Peter N.; Hursthouse, Michael B.; Crystal Structure Report Archive  (2002) 940–; doi:

data_1519508
_publ_section_title
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 C18H20N4O2
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_journal_name_full               'Crystal Structure Report Archive'
_journal_page_first              940
_journal_year                    2002
_chemical_formula_sum            'C18 H20 N4 O2'
_chemical_formula_weight         324.38
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   10.6683(3)
_cell_length_b                   10.8869(3)
_cell_length_c                   29.9190(8)
_cell_measurement_reflns_used    4016
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.485
_cell_measurement_theta_min      2.910
_cell_volume                     3474.93(17)
_computing_cell_refinement
' DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998)'
_computing_data_collection       ' DENZO (Otwinowski and Minor, 1997)'
_computing_data_reduction
' DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998)'
_computing_molecular_graphics    'PLATON (Spek, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997b)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997a)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Nonius KappaCCD Area Detector'
_diffrn_measurement_method       '\f and \w scans to fill Ewald Sphere'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0560
_diffrn_reflns_av_sigmaI/netI    0.0637
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            11806
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         3.33
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_T_max  0.9917
_exptl_absorpt_correction_T_min  0.9835
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SORTAV Blessing (1997)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.240
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             1376
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.162
_refine_diff_density_min         -0.259
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.966
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         3047
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.966
_refine_ls_R_factor_all          0.0844
_refine_ls_R_factor_gt           0.0452
_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^)+(0.0545P)^2^+0.3280P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0947
_refine_ls_wR_factor_ref         0.1103
_reflns_number_gt                2027
_reflns_number_total             3047
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            eCrystal-940.cif
_cod_data_source_block           s92
_cod_depositor_comments
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Citation :
Jones, Ray C.F. and Horton, Peter N. and Hursthouse, Michael B. (2002) 
University of Southampton, Crystal Structure Report Archive. 
(doi:10.5258/ecrystals/940)

More at:
http://ecrystals.chem.soton.ac.uk/940/

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to the built-in table from CIF Core
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 3271 2015-04-21 07:52:19Z andrius 
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_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               1519508