**************** The 19th., Lab Seminar *****************

Date: Thu, February 26, 2004  PM 4:00-

Place: No.616 Seminar room
　　　　　　 Graduate School of Information Science

Speaker: Yusuke Ohta

Title: A Priori Evaluation of Aqueous Polarization Effects Through Monte
Carlo QM - MM Simulations
 J. Gao and X. Xia
 Science, New Series, Vol. 258, No. 5082 (Oct. 23, 1992), 631-635
　　　　　
Abstract:
 A Monte Carlo QM-MM (quantum mechanical - molecular mechanical) simulation
method has determined the contributions of the solvent polarization effect
to the total interaction energy between solute and solvent for amino acid
etc. in aqueous solution. In the present AM1-TIP3P approach, the solute
molecule is characterized by valence electrons etc. with Hartree - Fock
theory incorporating the solvent effects into the total Hamiltonian. The
polarization energy contributes 10 to 20 % of the total electrostatic energy
in these systems. The performance of the AM1-TIP3P model was further
validated by consideration of bimolecular complexes with water and by
computation of the free energies of solvation of organic molecules using
statistical perturbation theory, and excellent agreement with ab initio
6-31G(d) results and experimental solvation free energies was obtained.

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