Molecular dynamics simulation with the charge response kernel: Vibrational spectra of liquid water and N-methylacetamide in aqueous solution

New polarizable and flexible water models are developed using the charge response kernels obtained by ab initio calculations. MD simulations are carried out for three-and five-site models to compute the infrared (IR) and Raman spectra of liquid water at ambient conditions, and results are compared with those from other water models. On the basis of those calculations, we devised a new polarizable and flexible five-site model for the water molecule which can well reproduce the experimental spectral features. The model is also applied to computing the IR spectrum of N-methylacetamide in aqueous solution. The results imply the importance of the polarization effect for precise modeling of the intermolecular interaction.