Induced dipole moment and atomic charges based on average electrostatic potentials in aqueous solution

• Published in: The Journal of chemical physics 1993-02, Vol.98 (4), p.2975-2982
• Main Authors: JIALI GAO, LUQUE, F. J, OROZCO, M
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Physics
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.464126

A Monte Carlo quantum mechanical and molecular mechanical (QM/MM) simulation method using the combined Austin model 1 (AM1) and TIP3P potential is proposed to evaluate the average molecular electrostatic potentials (MEP) in aqueous solution. It was demonstrated that the average MEP in water can provide a quantitative account of the solvent polarization effect on molecular dipole moments and atomic charges. The computed induced dipole moments from the Monte Carlo AM1/TIP3P simulation method were found to be in good agreement with those predicted by continuum self-consistent reaction field theory using the AM1 and 6-31G(d) wave functions. The findings also indicate that the minimal basis set adopted by the AM1 method can capture the solvent effect effectively. Finally, good correlations in the MEP-fitted charges were obtained between different methods. These results should be useful for developing polarizable intermolecular potential functions (PIPF).