Simple Liquids

Of the three basic states of matter, liquids require far more sophisticated theoretical models than gases or solids. The former may be treated to a first approximation as an ideal gas, the latter by a harmonic bead-spring model. No such straightforward analytical approaches exist for liquids which combine the disorder of gases and the strong correlations of solids. In other words, there is no obvious smallness parameter to be implemented, which makes the description of the liquid state rather challenging (Hansen and MacDonald, 2006)…