5-Fluorouracil and thymine form a crystalline solid solution
Barnett, Sarah A.; Hulme, Ashley T.; Tocher, Derek A.; Acta Crystallographica Section C 62 (2006) o412–o415; doi:10.1107/S0108270106019688

data_2015434
_publ_section_title
;
 5-Fluorouracil and thymine form a crystalline solid solution
;
_journal_coeditor_code           GG3013
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o412
_journal_page_last               o415
_journal_paper_doi               10.1107/S0108270106019688
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac
'C4.48 H4.45 F0.52 N2 O2, C4.30 H3.91 F0.70 N2 O2'
_chemical_formula_moiety
'C4.48 H4.45 F0.52 N2 O2, C4.30 H3.91 F0.70 N2 O2'
_chemical_formula_sum            'C8.78 H8.34 F1.22 N4 O4'
_chemical_formula_weight         257.07
_chemical_name_common            5-fluorouracil--thymine
_chemical_name_systematic
;
5-fluoropyrimidine-2,4(1H,3H)-dione--5-methylpyrimidine-2,4(1H,3H)-dione
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 117.8130(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   19.3785(15)
_cell_length_b                   5.9918(5)
_cell_length_c                   20.0293(15)
_cell_measurement_reflns_used    4174
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.916
_cell_measurement_theta_min      2.300
_cell_volume                     2057.0(3)
_computing_cell_refinement       'SAINT (Bruker, 1998)'
_computing_data_collection       'SMART (Bruker, 1998)'
_computing_data_reduction        SAINT
_computing_publication_material
;
CAMERON (Watkin <i>et al.</i>,  1996) and Mercury (Macrae <i>et al.</i>,
 2006)
;
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.966
_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  0.0155
_diffrn_reflns_av_sigmaI/netI    0.0163
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            8568
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         28.26
_diffrn_reflns_theta_min         2.30
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.147
_exptl_absorpt_correction_T_max  0.9712
_exptl_absorpt_correction_T_min  0.8929
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.660
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'diamond tablet'
_exptl_crystal_F_000             1056
_exptl_crystal_size_max          0.79
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.346
_refine_diff_density_min         -0.187
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.059
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     207
_refine_ls_number_reflns         2459
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.062
_refine_ls_R_factor_all          0.0407
_refine_ls_R_factor_gt           0.0369
_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^)+(0.0452P)^2^+1.6915P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0930
_refine_ls_wR_factor_ref         0.0955
_reflns_number_gt                2232
_reflns_number_total             2459
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gg3013.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2015434
_cod_database_fobs_code          2015434