Anhydrous guanine: a synchrotron study
Guille, Kathy; Clegg, William; Acta Crystallographica Section C 62 (2006) o515–o517; doi:10.1107/S0108270106026011

data_2015488
_publ_section_title
;
 Anhydrous guanine: a synchrotron study
;
_journal_coeditor_code           GD3036
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o515
_journal_page_last               o517
_journal_paper_doi               10.1107/S0108270106026011
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C5 H5 N5 O'
_chemical_formula_moiety         'C5 H5 N5 O'
_chemical_formula_sum            'C5 H5 N5 O'
_chemical_formula_weight         151.14
_chemical_name_common            guanine
_chemical_name_systematic
;
2-amino-1,7-dihydro-6H-purin-6-one
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 95.748(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   3.5530(16)
_cell_length_b                   9.693(4)
_cell_length_c                   16.345(7)
_cell_measurement_reflns_used    856
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      21.5
_cell_measurement_theta_min      2.3
_cell_volume                     560.1(4)
_computing_cell_refinement       'SAINT (Bruker, 2004)'
_computing_data_collection       'APEX2 (Bruker, 2004)'
_computing_data_reduction        SAINT
_computing_molecular_graphics
'SHELXTL and DIAMOND (Brandenburg & Putz, 2004)'
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  'SHELXTL (Sheldrick, 2001)'
_computing_structure_solution    'SIR2002 (Burla <i>et al.</i>,  2003)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker APEX2 CCD area-detector'
_diffrn_measurement_method       'thin-slice \w'
_diffrn_radiation_monochromator  'silicon 111'
_diffrn_radiation_source         'Daresbury SRS station 9.8'
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.6712
_diffrn_reflns_av_R_equivalents  0.0539
_diffrn_reflns_av_sigmaI/netI    0.0431
_diffrn_reflns_limit_h_max       3
_diffrn_reflns_limit_h_min       -3
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            3444
_diffrn_reflns_theta_full        21.92
_diffrn_reflns_theta_max         21.92
_diffrn_reflns_theta_min         2.31
_diffrn_standards_decay_%        5
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.136
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.792
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             312
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.340
_refine_ls_extinction_coef       0.12(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXTL (Sheldrick, 2001)'
_refine_ls_goodness_of_fit_ref   1.147
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     116
_refine_ls_number_reflns         795
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.147
_refine_ls_R_factor_all          0.0753
_refine_ls_R_factor_gt           0.0587
_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^)+(0.1065P)^2^+0.537P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1713
_refine_ls_wR_factor_ref         0.1831
_reflns_number_gt                624
_reflns_number_total             795
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gd3036.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2015488
_cod_database_fobs_code          2015488