 
data_try
 
_audit_creation_method            SHELXL-97
_chemical_name_systematic
;
 ?
;
_chemical_name_common             'melamine + uracil'
_chemical_melting_point           ?
_chemical_formula_moiety          'C3 H6 N6, C4 H4 N2 O2'
_chemical_formula_sum
 'C7 H10 N8 O2'
_chemical_formula_weight          238.23
 
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            'Monoclinic'
_symmetry_space_group_name_H-M    'C2/c'
 
loop_
 _symmetry_equiv_pos_as_xyz
 'x, y, z'
 '-x, y, -z+1/2'
 'x+1/2, y+1/2, z'
 '-x+1/2, y+1/2, -z+1/2'
 '-x, -y, -z'
 'x, -y, z-1/2'
 '-x+1/2, -y+1/2, -z'
 'x+1/2, -y+1/2, z-1/2'
 
_cell_length_a                    14.3618(10)
_cell_length_b                    7.5472(6)
_cell_length_c                    18.9922(14)
_cell_angle_alpha                 90.00
_cell_angle_beta                  91.838(4)
_cell_angle_gamma                 90.00
_cell_volume                      2057.5(3)
_cell_formula_units_Z             8
_cell_measurement_temperature     273(2)
_cell_measurement_reflns_used     145
_cell_measurement_theta_min       2
_cell_measurement_theta_max       25
 
_exptl_crystal_description        'rods'
_exptl_crystal_colour             'colourless'
_exptl_crystal_size_max           0.27
_exptl_crystal_size_mid           0.22
_exptl_crystal_size_min           0.15
_exptl_crystal_density_meas       ?
_exptl_crystal_density_diffrn     1.538
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000              992
_exptl_absorpt_coefficient_mu     0.120
_exptl_absorpt_correction_type    'none'
_exptl_absorpt_correction_T_min   ?
_exptl_absorpt_correction_T_max   ?
_exptl_absorpt_process_details    ?
 
_exptl_special_details
;
 ?
;
 
_diffrn_ambient_temperature       273(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   'Siemens Smart CCD diffractometer'
_diffrn_measurement_method        'W scans'
_diffrn_detector_area_resol_mean  ?
_diffrn_standards_number          ?
_diffrn_standards_interval_count  ?
_diffrn_standards_interval_time   ?
_diffrn_standards_decay_%         ?
_diffrn_reflns_number             4727
_diffrn_reflns_av_R_equivalents   0.0282
_diffrn_reflns_av_sigmaI/netI     0.0339
_diffrn_reflns_limit_h_min        -17
_diffrn_reflns_limit_h_max        17
_diffrn_reflns_limit_k_min        -9
_diffrn_reflns_limit_k_max        7
_diffrn_reflns_limit_l_min        -22
_diffrn_reflns_limit_l_max        22
_diffrn_reflns_theta_min          2.15
_diffrn_reflns_theta_max          25.39
_reflns_number_total              1861
_reflns_number_gt                 1543
_reflns_threshold_expression      >2sigma(I)
 
_computing_data_collection        'Siemns SMART'
_computing_cell_refinement        'HKL'
_computing_data_reduction         'HKL'
_computing_structure_solution     'SHELXTL97'
_computing_structure_refinement   'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics     ?
_computing_publication_material   'SHELXTL97'
 
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² 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/[σ²(Fo²)+(0.0736P)²+0.0000P] where P=(Fo²+2Fc²)/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      SHELXL
_refine_ls_extinction_coef        0.033(2)
_refine_ls_extinction_expression
 'Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^'
_refine_ls_number_reflns          1861
_refine_ls_number_parameters      195
_refine_ls_number_restraints      0
_refine_ls_R_factor_all           0.0443
_refine_ls_R_factor_gt            0.0373
_refine_ls_wR_factor_ref          0.1089
_refine_ls_wR_factor_gt           0.1053
_refine_ls_goodness_of_fit_ref    1.043
_refine_ls_restrained_S_all       1.043
_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
N5 N 0.62134(9) 0.10016(18) 0.57910(7) 0.0426(4) Uani 1 1 d . . .
N2 N 0.83388(8) -0.07115(17) 0.50089(6) 0.0405(3) Uani 1 1 d . . .
O2 O 0.71679(7) 0.08107(15) 0.44482(5) 0.0485(3) Uani 1 1 d . . .
N8 N 0.60723(8) 0.02642(16) 0.69523(6) 0.0365(3) Uani 1 1 d . . .
N6 N 0.74881(8) -0.02204(16) 0.63454(6) 0.0364(3) Uani 1 1 d . . .
N7 N 0.74120(8) -0.09179(17) 0.75642(6) 0.0390(3) Uani 1 1 d . . .
O1 O 0.94496(8) -0.22806(18) 0.55922(6) 0.0564(4) Uani 1 1 d . . .
N1 N 0.83590(9) -0.02534(18) 0.38105(6) 0.0425(3) Uani 1 1 d . . .
C4 C 0.91796(11) -0.1160(2) 0.37882(8) 0.0460(4) Uani 1 1 d . . .
C6 C 0.78605(9) -0.07901(18) 0.69574(7) 0.0345(3) Uani 1 1 d . . .
N3 N 0.87690(9) -0.1249(2) 0.69775(7) 0.0469(4) Uani 1 1 d . . .
N4 N 0.60185(10) -0.0644(2) 0.81005(7) 0.0487(4) Uani 1 1 d . . .
C7 C 0.65989(9) 0.03451(18) 0.63742(7) 0.0333(3) Uani 1 1 d . . .
C5 C 0.65091(9) -0.04250(19) 0.75220(7) 0.0362(4) Uani 1 1 d . . .
C3 C 0.91516(10) -0.1680(2) 0.50274(8) 0.0415(4) Uani 1 1 d . . .
C2 C 0.95847(11) -0.1867(2) 0.43590(8) 0.0485(4) Uani 1 1 d . . .
C1 C 0.79059(10) 0.0000(2) 0.44230(7) 0.0381(4) Uani 1 1 d . . .
H7 H 0.9000(14) -0.157(3) 0.6553(11) 0.067(6) Uiso 1 1 d . . .
H3 H 0.9433(12) -0.128(2) 0.3338(9) 0.050(4) Uiso 1 1 d . . .
H9 H 0.6530(12) 0.102(2) 0.5413(10) 0.046(5) Uiso 1 1 d . . .
H2 H 0.8065(13) -0.056(2) 0.5422(11) 0.057(5) Uiso 1 1 d . . .
H4 H 1.0142(15) -0.258(3) 0.4338(10) 0.074(6) Uiso 1 1 d . . .
H10 H 0.5650(13) 0.141(2) 0.5803(8) 0.044(4) Uiso 1 1 d . . .
H6 H 0.5482(14) -0.026(2) 0.8098(9) 0.054(5) Uiso 1 1 d . . .
H8 H 0.8949(12) -0.194(2) 0.7341(10) 0.054(5) Uiso 1 1 d . . .
H1 H 0.8079(12) 0.019(2) 0.3416(11) 0.051(5) Uiso 1 1 d . . .
H5 H 0.6299(12) -0.088(2) 0.8482(10) 0.042(4) Uiso 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
N5 0.0357(7) 0.0610(9) 0.0316(7) 0.0077(6) 0.0064(5) 0.0123(6)
N2 0.0364(7) 0.0560(8) 0.0292(7) -0.0004(5) 0.0043(5) 0.0073(5)
O2 0.0426(6) 0.0690(8) 0.0339(6) 0.0041(5) 0.0025(4) 0.0114(5)
N8 0.0323(6) 0.0476(7) 0.0299(6) -0.0004(5) 0.0053(4) 0.0015(5)
N6 0.0340(6) 0.0451(7) 0.0303(6) 0.0025(5) 0.0055(4) 0.0065(5)
N7 0.0370(6) 0.0516(8) 0.0287(6) 0.0022(5) 0.0039(5) 0.0044(5)
O1 0.0500(7) 0.0785(8) 0.0409(7) 0.0031(5) 0.0016(5) 0.0248(6)
N1 0.0470(7) 0.0520(8) 0.0288(7) -0.0004(5) 0.0049(5) -0.0002(6)
C4 0.0509(9) 0.0522(9) 0.0356(9) -0.0081(7) 0.0137(7) -0.0017(7)
C6 0.0355(7) 0.0382(8) 0.0300(7) -0.0005(5) 0.0036(5) 0.0021(5)
N3 0.0383(7) 0.0682(9) 0.0345(7) 0.0081(7) 0.0044(5) 0.0135(6)
N4 0.0365(7) 0.0793(11) 0.0308(7) 0.0091(6) 0.0070(6) 0.0047(7)
C7 0.0336(7) 0.0357(7) 0.0307(7) -0.0014(5) 0.0042(5) 0.0008(5)
C5 0.0362(7) 0.0431(8) 0.0296(7) -0.0015(6) 0.0037(5) -0.0023(6)
C3 0.0387(8) 0.0485(9) 0.0373(8) -0.0040(6) 0.0025(6) 0.0034(6)
C2 0.0445(9) 0.0554(10) 0.0461(9) -0.0087(7) 0.0100(7) 0.0075(7)
C1 0.0386(8) 0.0459(9) 0.0300(7) -0.0016(6) 0.0028(5) -0.0035(6)
 
_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
N5 C7 1.3190(18) . ?
N5 H9 0.862(18) . ?
N5 H10 0.867(18) . ?
N2 C1 1.3672(19) . ?
N2 C3 1.3768(19) . ?
N2 H2 0.90(2) . ?
O2 C1 1.2258(17) . ?
N8 C5 1.3385(19) . ?
N8 C7 1.3545(17) . ?
N6 C6 1.3350(18) . ?
N6 C7 1.3492(17) . ?
N7 C6 1.3416(18) . ?
N7 C5 1.3490(18) . ?
O1 C3 1.2286(18) . ?
N1 C1 1.3645(18) . ?
N1 C4 1.365(2) . ?
N1 H1 0.90(2) . ?
C4 C2 1.326(2) . ?
C4 H3 0.944(18) . ?
C6 N3 1.3492(19) . ?
N3 H7 0.91(2) . ?
N3 H8 0.898(18) . ?
N4 C5 1.3343(18) . ?
N4 H6 0.82(2) . ?
N4 H5 0.837(19) . ?
C3 C2 1.438(2) . ?
C2 H4 0.97(2) . ?
 
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
C7 N5 H9 119.2(11) . . ?
C7 N5 H10 118.5(11) . . ?
H9 N5 H10 122.3(16) . . ?
C1 N2 C3 126.34(12) . . ?
C1 N2 H2 117.4(12) . . ?
C3 N2 H2 116.3(12) . . ?
C5 N8 C7 114.42(12) . . ?
C6 N6 C7 114.83(11) . . ?
C6 N7 C5 114.61(12) . . ?
C1 N1 C4 122.19(13) . . ?
C1 N1 H1 116.3(11) . . ?
C4 N1 H1 121.5(11) . . ?
C2 C4 N1 122.22(13) . . ?
C2 C4 H3 122.1(10) . . ?
N1 C4 H3 115.7(10) . . ?
N6 C6 N7 125.52(13) . . ?
N6 C6 N3 117.87(12) . . ?
N7 C6 N3 116.60(12) . . ?
C6 N3 H7 114.9(12) . . ?
C6 N3 H8 115.2(11) . . ?
H7 N3 H8 114.8(16) . . ?
C5 N4 H6 118.1(13) . . ?
C5 N4 H5 119.1(11) . . ?
H6 N4 H5 120.3(17) . . ?
N5 C7 N6 117.21(12) . . ?
N5 C7 N8 117.86(12) . . ?
N6 C7 N8 124.92(12) . . ?
N4 C5 N8 117.89(13) . . ?
N4 C5 N7 116.67(13) . . ?
N8 C5 N7 125.44(12) . . ?
O1 C3 N2 119.31(13) . . ?
O1 C3 C2 125.87(14) . . ?
N2 C3 C2 114.82(14) . . ?
C4 C2 C3 119.43(15) . . ?
C4 C2 H4 122.1(12) . . ?
C3 C2 H4 118.3(12) . . ?
O2 C1 N1 122.67(13) . . ?
O2 C1 N2 122.38(12) . . ?
N1 C1 N2 114.95(13) . . ?
 
_diffrn_measured_fraction_theta_max    0.982
_diffrn_reflns_theta_full              25.39
_diffrn_measured_fraction_theta_full   0.982
_refine_diff_density_max    0.160
_refine_diff_density_min   -0.214
_refine_diff_density_rms    0.048
