1,7,9-Trimethyl-2,6-purinedione monohydrate, C~8~H~10~N~4~O~2~.H~2~O
Parvez, M.; Ferguson, G.; Acta Crystallographica Section C 50 (1994) 1303–1305; doi:10.1107/S0108270193012636

data_2009933
_publ_section_title
;
 1,7,9-Trimethyl-2,6-purinedione monohydrate, C~8~H~10~N~4~O~2~.H~2~O
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1303
_journal_page_last               1305
_journal_paper_doi               10.1107/S0108270193012636
_journal_volume                  50
_journal_year                    1994
_chemical_formula_moiety         'C8 H10 N4 O2,O1 H2'
_chemical_formula_sum            'C8 H12 N4 O3'
_chemical_formula_weight         212.2
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_type_scat_source           'Cromer & Mann (1968)'
_cell_angle_alpha                90.
_cell_angle_beta                 101.340(10)
_cell_angle_gamma                90.
_cell_formula_units_Z            4
_cell_length_a                   5.3570(10)
_cell_length_b                   17.759(3)
_cell_length_c                   10.2510(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      15
_cell_measurement_theta_min      10
_cell_volume                     956.2(3)
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.03
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2674
_diffrn_reflns_theta_max         27
_diffrn_standards_decay_%        none
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.11
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.47
_exptl_crystal_description       block
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.3
_refine_diff_density_min         -0.3
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_number_parameters     174
_refine_ls_number_reflns         1560
_refine_ls_R_factor_obs          0.046
_refine_ls_shift/esd_max         0.03
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/(\s^2^F + 0.0004F^2^)^1/2^'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.049
_reflns_number_observed          1560
_reflns_number_total             2082
_reflns_observed_criterion       I>3\s(I)
_cod_data_source_file            br1053.cif
_cod_data_source_block           br1053_structure_1_of_1
_cod_depositor_comments
;

    Removing symmetry operators '-x,-1/2+y,-1/2-z' and '-x,1/2-y,1/2+z',
    adding symmetry operator '-x,1/2+y,1/2-z' to
    '_symmetry_equiv_pos_as_xyz' loop, because:

    a) Old symmetry operators constituted 'P m c b' spacegroup, which is
       different from the one that is specified by publication authors;

    b) Fixed set of symmetry operators are full set of 'P 1 21/c 1'
       spacegroup symmetry operators;

    c) Reconstruction of cell contents using old symmetry operators
       resulted in steric clashes;

    d) After the replacement the contents of reconstructed cell matches
       formula 'C8 H12 N4 O3',  which is given by publication authors.

    Andrius Merkys
    2014-06-18

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value '1/(\s^2^F + 0.0004F^2^)^1/2^'
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^F +
0.0004F^2^)^1/2^'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        956.2(6)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2009933