Relationship between van der Waals corrections in ab initio molecular dynamics simulations and vibrational spectra of clathrate hydrate

Abstract

Ab initio molecular dynamics simulation is an effective method to obtain vibrational spectra, but it is known that there is a difficulty in the accuracy of van der Waals interaction. In this study, the effect of the correction for van der Waals interactions on the vibrational spectra of clathrate hydrates was examined, where hydrophobic interactions are important. As a result, it was found that the vibrational frequencies of the clathrate hydrates became smaller than those of PBE with the correction. However, vdw-DF2 and vdw-DF3-opt2 were found to reproduce the experimentally measured vibration frequency trends well.