A MOLECULAR DYNAMICS SIMULATION STUDY OF POLAR AND NONPOLAR GUEST MOLECULES IN BINARY sI CLATHRATE HYDRATE

We performed molecular dynamics simulation for polar and nonpolar guest molecules in structure I clathrate hydrate. We simulated TMO as guest in sI hydrate and compared with cyclobutane molecule which these two guests are isoelectric and have similar masses but are different dipole moment and hydrogen bonds ability. We showed snapshots of a large sI clathrate hydrate cage with a TMO guest molecule at 225 K. To determine the ability of the water model we investigated the radial distribution function for various guest species with four point charges TIP4P/ice and SPC/E water potential at different temperature and atmosphere pressure. For considering different dynamics of polar and nonpolar guest molecules in the clathrate hydrate we calculated velocity autocorrelation function (VACF) and Fourier transformation from VACF functions with TIP4P/ice and SPC/E water model at 250 K.