From NSDL Materials Digital Library Wiki
The Weeks-Chandler-Andersen potential (WCA) is a short range, purely repulsive interaction potential. It is meant to model excluded volume interaction and short range repulsion. The WCA potential is constructed by truncating The Lennard-Jones Potential at the 2(1 / 6)σ, corresponding to the minimum in the potential well, and shifting the entire potential by The Lennard-Jones Potential well depth, ε. The WCA potential can be expressed mathematically as:
This potential decays smoothly to zero at 2(1 / 6)σ.