RKMAG is a software based on using eigenvalue method, as described in the article: http://www.rkmag.com/articles/abs2.pdf to calculate the absorption spectra of magnetic bodies, together with magnetostatic spin waves and their frequencies.
The main advantage of the method is that one can calculate at once the absorption spectra for arbitrary r.f. fields or spintronic currents, together with all of the resonant modes; one does not need to repeat the calculations if the absorption spectrum for a different r.f. field is desired.
In addition, the code is capable to calculate behavior of systems composed of different materials; account for Slontzwesky spin torque (spintronics); partially parallelized.