A coupled density functional-molecular mechanics Monte Carlo simulation method: The water molecule in liquid water

✍ Scribed by Tu��n, I.; Martins-Costa, M. T. C.; Millot, C.; Ruiz-L�pez, M. F.; Rivail, J. L.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 819 KB
• Volume: 17
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/(sici)1096-987x(19960115)17:1<19::aid-jcc2>3.0.co;2-3

✦ Synopsis

A theoretical model to investigate chemical processes in solution is described. It is based on the use of a coupled density functional/molecular mechanics Hamiltonian. The most interesting feature of the method is that it allows a detailed study of the solute's electronic distribution and of its fluctuations. We present the results for isothermal-isobaric constant-NPT Monte Carlo simulation of a water molecule in liquid water. The quantum subsystem is described using a double-zeta quality basis set with polarization orbitals and nonlocal exchange-correlation corrections. The classical system is constituted by 128 classical TIP3P or Simple Point Charge (SPC) water molecules. The atom-atom radial distribution functions present a good agreement with the experimental curves. Differences with respect to the classical simulation are discussed. The instantaneous and the averaged polarization of the quantum molecule are also analyzed.