An integrated effective fragment-polarizable continuum approach to solvation: Theory and application to glycine

摘要

A new discrete/continuum solvation model has been developed by combining the effective fragment potential (EFP) for the discrete part and the plarizable continuum model (PCM) for the continuum part. The usefulnes of this model is demonstrated by applying it to the calculation of the relatie energies of the neutral and zwitterionic forms of glycine. These calcualtions wer performed by treating glycine with ab initio wave functions. Water clusters were treated with both ab initio and EFP methods for comparison purposes, and the effect of the continuum was accounted for by the PCM moel. the energy barrier connecting the zwitteriionic and neutral three-water clusters was also examined. The computationally efficient EFP/PCM model gives results that are in close agreement with the much more expensive full ab initio/PCM claculation. The use of methods that account for electron correlation is necessary to obtain accurate relative energies for the isoemrs of glycine.