Three Polymorphs of 2-Amino-5-nitropyrimidine: Experimental Structures and Theoretical Predictions
Christer B. Aakeröy; Mark Nieuwenhuyzen; Sarah L. Price; Journal of the American Chemical Society 120 (1998) 8986–8993; doi:10.1021/ja981122i

data_4116827
_publ_section_title
;
 Three Polymorphs of 2-Amino-5-nitropyrimidine: Experimental Structures
 and Theoretical Predictions
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              8986
_journal_page_last               8993
_journal_paper_doi               10.1021/ja981122i
_journal_volume                  120
_journal_year                    1998
_chemical_formula_sum            'C4 H4 N4 O2'
_chemical_formula_weight         140.11
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 104.37
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.128
_cell_length_b                   17.500(2)
_cell_length_c                   6.8720(10)
_cell_measurement_temperature    293(2)
_cell_volume                     597.40(11)
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_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  0.0224
_diffrn_reflns_av_sigmaI/netI    0.0464
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            1518
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.33
_exptl_absorpt_coefficient_mu    0.128
_exptl_crystal_density_diffrn    1.558
_exptl_crystal_F_000             288
_refine_diff_density_max         0.139
_refine_diff_density_min         -0.162
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.004
_refine_ls_goodness_of_fit_obs   1.130
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1048
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.004
_refine_ls_restrained_S_obs      1.130
_refine_ls_R_factor_all          0.1220
_refine_ls_R_factor_obs          0.0515
_refine_ls_shift/esd_max         0.017
_refine_ls_shift/esd_mean        0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0381P)^2^+0.3106P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1212
_refine_ls_wR_factor_obs         0.0926
_reflns_number_observed          529
_reflns_number_total             1048
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja981122i_1.cif
_cod_data_source_block           form1
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0381P)^2^+0.3106P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0381P)^2^+0.3106P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               4116827