Seminar
Quantum Simulations of Biomolecules: Accurate Potentials from Spectroscopy
Professor R. B. Gerber
Department of Physical Chemistry and
The Fritz Haber Research Center,
The Hebrew University, Jerusalem, Israel
and
Department of Chemistry
University of California, Irvine CA
Monday, February 8, 1999
3:00 pm
3269 Beckman Institute
A new approach for obtaining accurate force fields for biological molecules and related systems is described. Fitting of high-resolution vibrational spectroscopy is the source of the most accurate potentials for small molecules available at present, but until recently this approach could not be applied for large molecules. Recent developments have completely changed the situation, leading to determination of much improved force fields from spectroscopic data. The theoretical progress that made this possible is a method for computing the vibrational spectroscopy of systems having many coupled anharmonic degrees of freedom. The method is outlined, and first applications are described to the determination of new, accurate potentials for water clusters, ion-water complexes, peptides, peptide-water complexes, and monosaccharides. Calculations for proteins, including hydration water are carried out, demonstrating that their vibrational spectroscopy at low tempertures is assignable and sensitive to the potential function. The prospects for providing an extensive set of potential functions derived from spectroscopy for simulations of biomolecules is discussed.
