Harmonic repulsion potential

The Harmonic repulsion potential, designed for studies of polymer micelles, dendrimers, and colloidal particles, is given by ( Eq. 2):

\[ \Phi_{12}\left( r \right) = \left\{ \begin{array}{lll} \frac{\epsilon}{2} (1-r/\sigma)^{2} & ; & r < \sigma \\ 0 & ; & r \geq \sigma \end{array} \right. \]

where \( \Phi_{12}\left( r \right) \) is the intermolecular pair potential, \(r := |\mathbf{r}_1 - \mathbf{r}_2|\) is the distance between site 1 and site 2. \(\sigma\) represents a length scale and \(\epsilon\) an energy. For example, for \(\epsilon=20\) the potential looks like

Phase diagram

The phase diagram in the pressure-temperature plane has been calculated by Zhu and Lu .

See also

• Hertzian sphere model