N-6 Lennard-Jones potential

The n-6 Lennard-Jones potential is a variant the more well known Lennard-Jones model (or from a different point of view, a particular case of the Mie potential).. The potential is given by ^[1]:

\Phi _{12}(r)=\epsilon \left({\frac {n}{n-6}}\right)\left({\frac {n}{6}}\right)^{\frac {6}{n-6}}\left[\left({\frac {\sigma }{r}}\right)^{n}-\left({\frac {\sigma }{r}}\right)^{6}\right]

where

$r:=|\mathbf {r} _{1}-\mathbf {r} _{2}|$
$\Phi _{12}(r)$ is the intermolecular pair potential between two particles, "1" and "2".
$\sigma$ is the diameter (length), i.e. the value of $r$ at which $\Phi _{12}(r)=0$
$\epsilon$ is the well depth (energy)