A computational and experimental search for polymorphs of parabanic acid ‒ a salutary tale leading to the crystal structure of oxo-ureido-acetic acid methyl esterElectronic supplementary information (ESI) available: crystal structures of the 16 lattice energy minima in Table 2, in the space group setting used in the minimisation. See http://www.rsc.org/suppdata/ce/b2/b211784c/
Lewis, T. C.; Tocher, D. A.; Day, G. M.; Price, S. L.; CrystEngComm 5 (2003) 3–; doi:10.1039/b211784c

data_7204575
_publ_section_title
;
 A computational and experimental search for polymorphs of parabanic
 acid -- a salutary tale leading to the crystal structure of
 oxo-ureido-acetic acid methyl esterElectronic supplementary
 information (ESI) available: crystal structures of the 16 lattice
 energy minima in Table 2, in the space group setting used in the
 minimisation. See http://www.rsc.org/suppdata/ce/b2/b211784c/
;
_journal_issue                   2
_journal_name_full               CrystEngComm
_journal_page_first              3
_journal_paper_doi               10.1039/b211784c
_journal_volume                  5
_journal_year                    2003
_chemical_formula_sum            'C4 H6 N2 O4'
_chemical_formula_weight         146.11
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                70.112(4)
_cell_angle_beta                 85.814(4)
_cell_angle_gamma                74.095(4)
_cell_formula_units_Z            2
_cell_length_a                   5.5028(13)
_cell_length_b                   7.0583(16)
_cell_length_c                   8.2718(19)
_cell_measurement_temperature    150(2)
_cell_volume                     290.48(12)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.923
_diffrn_measurement_device_type  'Bruker SMART APEX diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_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  0.0158
_diffrn_reflns_av_sigmaI/netI    0.0217
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            2431
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         27.98
_diffrn_reflns_theta_min         2.62
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.151
_exptl_absorpt_correction_T_max  0.9940
_exptl_absorpt_correction_T_min  0.9734
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.670
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             152
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.403
_refine_diff_density_min         -0.259
_refine_diff_density_rms         0.060
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.054
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     104
_refine_ls_number_reflns         1294
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.054
_refine_ls_R_factor_all          0.0408
_refine_ls_R_factor_gt           0.0379
_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^)+(0.0713P)^2^+0.0622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1048
_refine_ls_wR_factor_ref         0.1075
_reflns_number_gt                1197
_reflns_number_total             1294
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            b211784c.txt
_cod_data_source_block           str0039
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7204575