ISSN:
1432-2234
Keywords:
Hemin
;
Hyperfine properties
;
First-principles UHF
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary As part of a program for first-principles quantitative study of hyperfine properties of large biological molecules, we have applied the Self-Consistent Field Unrestricted Hartree-Fock procedure to investigate the electronic structure of hemin, the associated charge and unpaired spin population distributions and the hyperfine constants of57Fe,14N,13C,1H and35Cl nuclei. The results of the present work indicate significantly more localized charge and spin distributions than were found earlier by the semi-empirical Self-Consistent Charge Extended Hückel procedure. The theoretical values of the57Fe,14N and methene proton hyperfine constants, the only nuclei for which experimental data are available, are found to be −34.99, 11.89 and −1.50 MHz in satisfactory agreement with the experimental values of −26.47, 7.55 and −1.014 MHz, respectively. The contact and dipolar contributions to the hyperfine constants and their breakdowns into direct and exchange polarization contributions are analyzed. Possible sources that could bridge the remaining gap between experiment and theory will be analyzed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01113259
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