This workshop is to be organised jointly by Dr A J Masters (Manchester, UK) and Professor M. P. Allen (Warwick, UK).
The main techniques traditionally used to calculate the equilibrium properties of homogeneous, isotropic fluids are: (a) a virial expansion; (b) integral equation theory; (c) perturbation methods around a known reference system.
By the end of the 1970s, these methods had been developed to a very sophisticated level, so that it was possible, for the most part, to calculate very accurate thermodynamic and structural properties for fluids of spherical particles.
Since that time, many further significant advances have been made. While space does not permit anything like a comprehensive list, we give just a few developments. One is Wertheims associating fluid theory, which, for example, provides an accurate and computationally straightforward way to treat chain molecules. A second is the development of efficient numerical algorithms to solve integral equation theories for the isotropic phase of axially symmetric molecules. A third is the advent of reference interaction site theories (RISM, PRISM, etc). A fourth is the growth of density functional theories which aim to describe inhomogeneous fluids. Fundamental Measure Theory has had a major impact in this field in recent times. Finally we note that methodologies have recently been developed to calculate the 8th to 10th order virial coefficients, re-invigorating this particular theoretical approach.
The recent explosion of interest in colloidal systems has given liquid state theory a fresh impetus. Compared to simple liquids the potentials of interaction between the colloidal particles are relatively straightforward, so all the liquid state methods can be employed without the need to agonize over the accuracy of molecular pair potentials of interaction. These particles also form ordered phases, such as liquid crystals and various forms of crystal, and again there is a need to describe these phases theoretically. Another related development is in the study of systems whose particles interact via soft, integrable pair potentials. Such potentials appear in dissipative particle dynamics simulations and in configurationally averaged potentials that describe the interactions of two polymers. Theories such as the high temperature approximation and random phase approximation, developed in the 1970s, work very well for these systems and this has again engendered much theoretical work.