Triangular well model

The triangular well model is given by

\Phi \left(r\right)=\left\{{\begin{array}{ccc}\infty &;&r\leq \sigma \\{\frac {\epsilon (r/\sigma -\lambda )}{(\lambda -1)}}&;&\sigma <r\leq \lambda \sigma \\0&;&r>\lambda \sigma \end{array}}\right.

where $\Phi (r)$ is the intermolecular pair potential, $r$ is the distance, $\sigma$ is the hard diameter, $\epsilon$ is the well depth and λ > 1.

Equation of state

Main article: Equations of state for the triangular well model