#------------------------------------------------------------------------------ #$Date: 2008-01-14 00:15:36 +0200 (Mon, 14 Jan 2008) $ #$Revision: 14 $ #$URL: file:///home/coder/svn-repositories/cod/cif/2/2003051.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/ # # All data on this site have been placed in the public domain by the # contributors. # data_2003051 _journal_name_full 'Acta Crystallographica, Section B' _journal_year 1999 _journal_volume B55 _journal_page_first 78 _journal_page_last 84 _publ_section_title ; Experimental Charge Density and Electrostatic Potential in Nicotinamide ; loop_ _publ_author_name 'YOSHIHISA MIWA' 'TAKASHI MIZUNO' 'KAZUNORI TSUCHIDA' 'TOORU TAGA' 'YUTAKA IWATA' _publ_section_synopsis ; The accurate crystal structure of nicotinamide was determined from the X-ray and the neutron diffraction experiments. The electron distribution determined by the maximum entropy method show that the electrostatic properties depend on the rotation of carboxyamide group for the pyridine plane. ; _chemical_name_common nicotinamide _chemical_formula_sum 'C6 H6 N2 O1' _chemical_formula_weight 122.13 _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M P21/c loop_ _symmetry_equiv_pos_as_xyz '+X,+Y,+Z' '-X,1/2+Y,1/2-Z' _cell_length_a 3.877(4) _cell_length_b 15.600(10) _cell_length_c 9.375(6) _cell_angle_alpha 90 _cell_angle_beta 98.45(7) _cell_angle_gamma 90 _cell_volume 560.8 _cell_formula_units_Z 4 _cell_measurement_reflns_used 25 _cell_measurement_theta_min 8.41 _cell_measurement_theta_max 13.46 _cell_measurement_temperature 150 _exptl_crystal_description ? _exptl_crystal_colour colorless _exptl_crystal_size_max 0.70 _exptl_crystal_size_mid 0.70 _exptl_crystal_size_min 0.60 _exptl_crystal_density_diffrn 1.4463 _exptl_crystal_density_meas ' 1.398 (at room temp.)' _exptl_crystal_density_method ? _exptl_crystal_F_000 256 _exptl_absorpt_coefficient_mu 0.103 _exptl_absorpt_correction_type none _diffrn_ambient_temperature 150 _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_source rotarix _diffrn_radiation_monochromator graphite _diffrn_measurement_device 'Rigaku AFC5-RU200' _diffrn_measurement_method \w/2\q _diffrn_reflns_number 6781 _diffrn_reflns_av_R_equivalents 0.024 _diffrn_reflns_theta_min 1 _diffrn_reflns_theta_max 55 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 8 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 35 _diffrn_reflns_limit_l_min -21 _diffrn_reflns_limit_l_max 21 _diffrn_reflns_reduction_process 'MSC/AFC (MSC, 1988)' _diffrn_standards_number 3 _diffrn_standards_interval_count 150 _diffrn_standards_decay_% 8 _reflns_number_total 6199 _reflns_number_observed 4810 _reflns_observed_criterion F>3\s(F) _refine_ls_structure_factor_coef F _refine_ls_matrix_type 'Full-matrix least-squares' _refine_ls_R_factor_obs 0.054 _refine_ls_wR_factor_obs 0.056 _refine_ls_goodness_of_fit_obs 0.29 _refine_ls_number_reflns 4810 _refine_ls_number_parameters 106 _refine_ls_hydrogen_treatment 'refxyz all from D-map ' _refine_ls_weighting_scheme 'w=1/[\s^2^(F)+0.08F^2^]' _refine_ls_shift/esd_max 0.01 _refine_diff_density_max 0.466 _refine_diff_density_min -0.258 _refine_ls_extinction_method none loop_ _atom_type_symbol _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C 0.002 0.002 International_Tables_Vol_IV_Table_2.2B H 0.000 0.000 International_Tables_Vol_IV_Table_2.2B N 0.004 0.003 International_Tables_Vol_IV_Table_2.2B O 0.008 0.006 International_Tables_Vol_IV_Table_2.2B loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_thermal_displace_type C2 -0.0384(2) 0.33937(4) 0.19344(6) .01989(8) Ueq C3 0.15280(10) 0.35815(4) 0.32749(5) .01734(8) Ueq C4 0.1745(2) 0.44285(4) 0.37152(6) .02310(10) Ueq C5 0.0184(2) 0.50592(4) 0.28065(7) .0265(2) Ueq C6 -0.1644(2) 0.48110(4) 0.14914(7) .0235(2) Ueq C7 0.3283(2) 0.29179(4) 0.42823(5) .01934(8) Ueq N1 -0.19760(10) 0.39949(3) 0.10545(5) .02188(8) Ueq N2 0.4058(2) 0.21699(4) 0.37214(6) .02400(10) Ueq O1 0.39630(10) 0.30857(3) 0.55835(4) .02720(10) Ueq H2 -0.083(3) 0.2843(6) 0.1580(10) .029(3) Uiso H4 0.312(3) 0.4549(7) 0.4730(10) .039(3) Uiso H5 0.023(3) 0.5620(8) 0.3140(10) .043(3) Uiso H6 -0.275(3) 0.5229(7) 0.0790(10) .034(3) Uiso H2A 0.400(3) 0.2102(7) 0.2780(10) .047(3) Uiso H2B 0.511(3) 0.1770(7) 0.4340(10) .052(4) Uiso loop_ _atom_site_aniso_label _atom_site_aniso_u_11 _atom_site_aniso_u_22 _atom_site_aniso_u_33 _atom_site_aniso_u_12 _atom_site_aniso_u_13 _atom_site_aniso_u_23 C2 .0237(2) .0196(2) .0143(2) -.0006(2) -.0033(2) -.00060(10) C3 .0198(2) .0190(2) .0127(2) -.0025(2) -.00150(10) .00010(10) C4 .0279(3) .0207(2) .0183(2) -.0032(2) -.0036(2) -.00230(10) C5 .0342(3) .0184(2) .0247(3) -.0008(2) -.0021(2) -.0012(2) C6 .0277(3) .0211(2) .0204(2) .0020(2) -.0008(2) .00260(10) C7 .0229(2) .0205(2) .0128(2) -.0028(2) -.00230(10) .00150(10) N1 .0258(2) .0219(2) .0156(2) .0015(2) -.00360(10) .00100(10) N2 .0331(3) .0207(2) .0156(2) .0019(2) -.0039(2) .00130(10) O1 .0385(3) .0281(2) .01230(10) .0005(2) -.00460(10) .00040(10)