  A numerical implementation of the transition state theory (TST) is presented
which can be used to calculate the attempt frequency $f_{0}$ of arbitrary
shaped magnetic nanostructures. The micromagnetic equations are discretized
using the finite element method. The climbing image nudged elastic band method
is used to calculate the saddle point configuration, which is required for the
calculation of $f_{0}$. Excellent agreement of the implemented numerical model
and analytical solutions is obtained for single domain particles. The developed
method is applied to compare $f_{0}$ for single phase and graded media grains
of advanced recording media. $f_{0}$ is predicted to be comparable if the
maximum anisotropy is the same in these two media types.
