Experimental and theoretical charge density study of polymorphic isonicotinamide-oxalic acid molecular complexes with strong O...H...N hydrogen bonds.
Schmidtmann, Marc; Farrugia, Louis J.; Middlemiss, Derek S.; Gutmann, Matthias J.; McIntyre, Garry J.; Wilson, Chick C.; The journal of physical chemistry. A 113 (2009) 13985–13997; doi:10.1021/jp9067813

data_1516359
_publ_section_title
;
 Experimental and theoretical charge density study of polymorphic
 isonicotinamide-oxalic acid molecular complexes with strong O...H...N
 hydrogen bonds.
;
_journal_issue                   50
_journal_name_full               'The journal of physical chemistry. A'
_journal_page_first              13985
_journal_page_last               13997
_journal_paper_doi               10.1021/jp9067813
_journal_volume                  113
_journal_year                    2009
_chemical_formula_sum            'C14 H14 N4 O6'
_chemical_formula_weight         334.29
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 102.70(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.720(5)
_cell_length_b                   10.014(6)
_cell_length_c                   12.187(6)
_cell_measurement_temperature    100(2)
_cell_volume                     1395.3(12)
_computing_cell_refinement       SXD-2001
_computing_data_collection       SXD-2001
_computing_data_reduction        SXD-2001
_computing_molecular_graphics    'Bruker AXS XP'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measurement_device_type  'SXD time-of-flight LAUE diffraction'
_diffrn_measurement_method       'time-of-flight LAUE diffraction'
_diffrn_radiation_source         'ISIS spallation source'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.69-6.98
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0607
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            8486
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.591
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             452
_exptl_crystal_size_max          3.0
_exptl_crystal_size_mid          2.0
_exptl_crystal_size_min          2.0
_refine_diff_density_max         2.581
_refine_diff_density_min         -2.088
_refine_diff_density_rms         0.531
_refine_ls_extinction_coef       0.00411(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    refined
_refine_ls_matrix_type           full
_refine_ls_number_parameters     178
_refine_ls_number_reflns         8486
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0658
_refine_ls_R_factor_gt           0.0658
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0700P)^2^+90.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1616
_refine_ls_wR_factor_ref         0.1616
_reflns_number_gt                8486
_reflns_number_total             8486
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            1-I_neutron.cif
_cod_data_source_block           oxasxd3d
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               1516359