  This paper presents an overview of the Fokker-Planck formalism for
non-biological magnetic resonance simulations, describes its existing
applications and proposes some novel ones. The most attractive feature of
Fokker-Planck theory compared to the commonly used Liouville - von Neumann
equation is that, for all relevant types of spatial dynamics (spinning,
diffusion, flow, etc.), the corresponding Fokker-Planck Hamiltonian is
time-independent. Many difficult NMR, EPR and MRI simulation problems (multiple
rotation NMR, ultrafast NMR, gradient-based zero-quantum filters, diffusion and
flow NMR, off-resonance soft microwave pulses in EPR, spin-spin coupling
effects in MRI, etc.) are simplified significantly in Fokker-Planck space. The
paper also summarises the author's experiences with writing and using the
corresponding modules of the Spinach library - the methods described below have
enabled a large variety of simulations previously considered too complicated
for routine practical use.
