Supplementary Material (ESI) for CrystEngComm This journal is (c) The Royal Society of Chemistry 2003 data_global _journal_coden_Cambridge 1350 loop_ _publ_author_name 'Sarah L. Price' 'G. M. Day' 'Thomas Lewis' 'D. Tocher' _publ_contact_author_name 'Prof Sarah L Price' _publ_contact_author_address ; Centre for Theoretical & Computational Chemistry UCL 20 Gordon Street London WC1H 0AJ UNITED KINGDOM ; _publ_contact_author_email S.L.PRICE@UCL.AC.UK _publ_requested_journal 'Cryst Eng. Comm.' _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 Ester. ; data_str0039 _database_code_CSD 198807 _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C4 H6 N2 O4' _chemical_formula_weight 146.11 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting triclinic _symmetry_space_group_name_H-M P-1 loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, -y, -z' _cell_length_a 5.5028(13) _cell_length_b 7.0583(16) _cell_length_c 8.2718(19) _cell_angle_alpha 70.112(4) _cell_angle_beta 85.814(4) _cell_angle_gamma 74.095(4) _cell_volume 290.48(12) _cell_formula_units_Z 2 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.18 _exptl_crystal_size_mid 0.18 _exptl_crystal_size_min 0.04 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.670 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 152 _exptl_absorpt_coefficient_mu 0.151 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.9734 _exptl_absorpt_correction_T_max 0.9940 _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Bruker SMART APEX diffractometer' _diffrn_measurement_method '\w rotation with narrow frames' _diffrn_detector_area_resol_mean ? _diffrn_standards_number 0 _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 2431 _diffrn_reflns_av_R_equivalents 0.0158 _diffrn_reflns_av_sigmaI/netI 0.0217 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_k_min -9 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_l_min -10 _diffrn_reflns_limit_l_max 10 _diffrn_reflns_theta_min 2.62 _diffrn_reflns_theta_max 27.98 _reflns_number_total 1294 _reflns_number_gt 1197 _reflns_threshold_expression I>2\s(I) _computing_data_collection 'Bruker SMART' _computing_cell_refinement 'Bruker SAINT' _computing_data_reduction 'Bruker SAINT' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ? _computing_publication_material ? _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0713P)^2^+0.0622P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 1294 _refine_ls_number_parameters 104 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0408 _refine_ls_R_factor_gt 0.0379 _refine_ls_wR_factor_ref 0.1075 _refine_ls_wR_factor_gt 0.1048 _refine_ls_goodness_of_fit_ref 1.054 _refine_ls_restrained_S_all 1.054 _refine_ls_shift/su_max 0.000 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group N1 N 0.7487(2) 0.92665(16) 0.13210(14) 0.0200(3) Uani 1 1 d . . . H1 H 0.833(4) 1.025(3) 0.094(2) 0.035(5) Uiso 1 1 d . . . C1 C 0.8357(2) 0.75753(18) 0.08768(15) 0.0158(3) Uani 1 1 d . . . C2 C 0.4989(2) 0.60531(19) 0.25113(15) 0.0163(3) Uani 1 1 d . . . C3 C 0.4139(2) 0.40408(18) 0.29279(15) 0.0169(3) Uani 1 1 d . . . C4 C 0.1223(2) 0.2207(2) 0.43363(17) 0.0210(3) Uani 1 1 d . . . H4A H 0.0821 0.1980 0.3293 0.032 Uiso 1 1 calc R . . H4B H -0.0293 0.2366 0.5030 0.032 Uiso 1 1 calc R . . H4C H 0.2554 0.1006 0.5004 0.032 Uiso 1 1 calc R . . N2 N 0.70212(19) 0.60337(16) 0.14670(13) 0.0169(3) Uani 1 1 d . . . H2A H 0.766(3) 0.491(3) 0.114(2) 0.023(4) Uiso 1 1 d . . . H2B H 0.604(3) 0.942(3) 0.198(2) 0.027(4) Uiso 1 1 d . . . O1 O 1.02424(17) 0.72479(14) 0.00029(12) 0.0214(2) Uani 1 1 d . . . O2 O 0.39496(17) 0.74200(15) 0.30988(12) 0.0230(3) Uani 1 1 d . . . O3 O 0.52775(18) 0.26207(15) 0.24454(14) 0.0267(3) Uani 1 1 d . . . O4 O 0.20952(16) 0.40952(14) 0.38618(12) 0.0191(2) Uani 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 N1 0.0204(5) 0.0148(5) 0.0293(6) -0.0141(4) 0.0095(4) -0.0059(4) C1 0.0162(6) 0.0131(5) 0.0194(6) -0.0084(4) 0.0034(4) -0.0029(4) C2 0.0149(6) 0.0145(6) 0.0204(6) -0.0091(5) 0.0034(4) -0.0020(4) C3 0.0143(5) 0.0164(6) 0.0204(6) -0.0085(5) 0.0044(4) -0.0029(4) C4 0.0208(6) 0.0170(6) 0.0264(6) -0.0083(5) 0.0079(5) -0.0072(5) N2 0.0173(5) 0.0129(5) 0.0229(5) -0.0107(4) 0.0068(4) -0.0036(4) O1 0.0218(5) 0.0176(4) 0.0297(5) -0.0149(4) 0.0133(4) -0.0072(4) O2 0.0215(5) 0.0195(5) 0.0333(5) -0.0176(4) 0.0127(4) -0.0059(4) O3 0.0264(5) 0.0188(5) 0.0413(6) -0.0197(4) 0.0173(4) -0.0085(4) O4 0.0172(5) 0.0158(4) 0.0260(5) -0.0102(4) 0.0087(4) -0.0050(3) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_2 _geom_bond_publ_flag N1 C1 1.3224(15) . ? C1 O1 1.2349(14) . ? C1 N2 1.4098(15) . ? C2 O2 1.2125(15) . ? C2 N2 1.3622(15) . ? C2 C3 1.5371(17) . ? C3 O3 1.2034(16) . ? C3 O4 1.3162(14) . ? C4 O4 1.4588(15) . ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag O1 C1 N1 125.06(11) . . ? O1 C1 N2 118.17(11) . . ? N1 C1 N2 116.76(10) . . ? O2 C2 N2 126.60(11) . . ? O2 C2 C3 122.05(10) . . ? N2 C2 C3 111.33(10) . . ? O3 C3 O4 126.25(11) . . ? O3 C3 C2 122.07(11) . . ? O4 C3 C2 111.67(10) . . ? C2 N2 C1 127.01(11) . . ? C3 O4 C4 114.40(10) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag O2 C2 C3 O3 -174.63(12) . . . . ? N2 C2 C3 O3 4.02(17) . . . . ? O2 C2 C3 O4 4.70(18) . . . . ? N2 C2 C3 O4 -176.66(9) . . . . ? O2 C2 N2 C1 1.1(2) . . . . ? C3 C2 N2 C1 -177.49(10) . . . . ? O1 C1 N2 C2 176.41(11) . . . . ? N1 C1 N2 C2 -3.12(18) . . . . ? O3 C3 O4 C4 0.66(19) . . . . ? C2 C3 O4 C4 -178.63(9) . . . . ? _diffrn_measured_fraction_theta_max 0.923 _diffrn_reflns_theta_full 26.00 _diffrn_measured_fraction_theta_full 0.982 _refine_diff_density_max 0.403 _refine_diff_density_min -0.259 _refine_diff_density_rms 0.060