# atsim.potentials.potentialfunctions¶

Functions for different potential forms.

Most of the potentials in this module are implemented as callable _Potential_Function_Bases. The potential energy is evaluated by calling one of these objects. By convention the first argument of each is the atomic separation r, with other potential parameters following after. For instance, to evaluate a Buckingham potential at r = 2.0 the following could be called for A, rho and C values 1000.0, 0.2 and 32.0 respectively:

atsim.potentialfunctions.buck(2.0, 1000.0, 0.2, 32.0)


The callable objects also have other useful methods. Perhaps most importantly is the .deriv() method this returns the first derivative of the given potential (force). Again using the Buckingham potential as an example its derivative can be evaluated for r = 2.0 as follows:

atsim.potentialfunctions.buck.deriv(2.0, 1000.0, 0.2, 32.0)


See List of Potential Forms for descriptions of these potential forms.

## Module Contents¶

atsim.potentials.potentialfunctions.buck[source]
atsim.potentials.potentialfunctions.bornmayer[source]
atsim.potentials.potentialfunctions.coul[source]
atsim.potentials.potentialfunctions.constant[source]
atsim.potentials.potentialfunctions.exponential[source]
atsim.potentials.potentialfunctions.hbnd[source]
atsim.potentials.potentialfunctions.lj[source]
atsim.potentials.potentialfunctions.morse[source]
atsim.potentials.potentialfunctions.polynomial[source]
atsim.potentials.potentialfunctions.sqrt[source]
atsim.potentials.potentialfunctions.tang_toennies[source]
atsim.potentials.potentialfunctions.zbl[source]
atsim.potentials.potentialfunctions.zero[source]
atsim.potentials.potentialfunctions.exp_spline[source]