Abstract
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 Rela2x, to automatically compute the analytic matrix representation of Γˆˆ for high-field NMR. Tools to analyse, approximate and visualize Γˆˆ are built into Rela2x. As a demonstration of the functionality, Γˆˆ is presented both for the familiar dipole-dipole coupled 1H-1H spin system and for more complicated 1H-14N and 1H-13C-14N systems with dipole-dipole coupling, chemical shift anisotropy and quadrupole interaction. We envision that the code will provide much-needed clarity in the form of a helpful tool for the study of relaxation effects, and constitute a reference source for scientists in the field of NMR.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have