# Weeks-Chandler-Andersen perturbation theory

The **Weeks-Chandler-Andersen perturbation theory** ^{[1]} is based on the following
decomposition of the intermolecular pair potential (in particular, the Lennard-Jones potential):

The reference system pair potential is given by (Eq, 4):

and the perturbation potential is given by (Eq, 5 Ref. 1):

## Ben-Amotz-Stell reformulation

^{[2]}

## Colloids

The repulsive component of the WCA decomposition has been used as a model for colloids ^{[3]}.

## References

- ↑ John D. Weeks, David Chandler and Hans C. Andersen "Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids", Journal of Chemical Physics
**54**pp. 5237-5247 (1971) - ↑ Dor Ben-Amotz and George Stell "Reformulation of Weeks-Chandler-Andersen Perturbation Theory Directly in Terms of a Hard-Sphere Reference System", Journal of Physical Chemistry B
**108**pp. 6877-6882 (2004) - ↑ L. Filion, R. Ni, D. Frenkel, and M. Dijkstra "Simulation of nucleation in almost hard-sphere colloids: The discrepancy between experiment and simulation persists", Journal of Chemical Physics
**134**134901 (2011)