Transfer of CH4 across the H2O-CCl4 liquid-liquid interface with polarizable potential models

Molecular dynamics simulations are carried out to investigate the free energy profile of transferring a methane molecule across the H2O-CCl4 liquid-liquid interface. The computed free energy curve decreases monotonically from bulk H2O to bulk CCl4. Examination of the solvation structures suggests that the transfer involves a smooth change of the composition of the solvation shell around CH4. The computed free energy of transfer estimated from the potential of mean force is 3.8 +/- 0.7 kcal/mol. This value is in good agreement with the value of 1.9 kcal/mol, supporting our approach.