Spin relaxation is modelled using the so-called relaxation superoperator Γˆˆ. Analytic forms of Γˆˆ have been derived in the literature in the simplest cases of one- or two-spin systems, with S=12 nuclei and no more than two different simultaneous relaxation mechanisms involved. Beyond that, for systems of more than two spins, with S>
12 and/or multiple relaxation mechanisms at play, the derivations become notoriously complicated, which is why analytic relaxation theory has mostly been considered a dead end. Instead, numerical methods of constructing Γˆˆ have been popular. However, they lack some of the physical, chemical and pedagogical insight that can be provided by analytic expressions. To this end, we present a general, interactive and freely available Python programme, named Rela