The HarmonicL0Bond interaction implements a simple harmonic bond potential with a zero rest length. The potential energy $V(r)$ for two covalently bonded atoms separated by a distance $r$ is given by

$V(r) = \frac{\kappa}{2} r^{2}$

Different values are defined for the spring constant $\epsilon$ for each bond type.

The values of $\kappa$ are given in the parameter file and source code by an array-valued variable named "kappa". The parameter file format is:

kappa Array<float>

The parameter block a system with two bond types (nBondType=2) might thus look like this:

kappa 100.0

150.0