Implementation

In this chapter, we will present the technical aspects of atomistic spin dynamics, in particular how the method can be implemented in an actual computer software. This involves calculation of effective field and creation of neighbour lists for setting up the geometry of the system of interest as well as choosing a suitable integrator scheme for the SLL (or SLLG) equation. We also give examples of extraction and processing of relevant observables that are common output from simulations. Atomistic spin dynamics simulations could be a computationally heavy tool but it is also very well adapted for modern computer architectures like massive parallel computing and/or graphics processing units and we provide examples how to utilize these architectures in an efficient manner. We use our own developed software UppASD as example, but the discussion could be applied to any other atomistic spin dynamics software.