A theoretical model may have multiple computational Methods, or implementations. Since a method is a numerical property, it always has a certain precision. A method is implemented inside a simulation engine (or application), and each application can itself implement one or more methods.
Example Model & Method
If we use Newtonian mechanics as Model, then the Method would be the algorithmic implementation of calculating the multiple between m and a in the
F = ma equation.
Methods in particular consist in the following two elements in the context of the computational aspects of a subworkflow calculation:
The type of inter-atomic potential modeling the various atomic interactions in the crystal structure under investigation. Please consult this page for a review of the available pseudopotential subtypes within the theoretical context of the DFT model.
The cutoff parameters in both the plane-wave and charge density expansions, again in the context of the DFT theory model, as explained here.