Of the conventions used, the Maryland (Ωκ) and Haeberlen (ζη) are the most commonly found conventions as both are recommended for reporting by IUPAC (Note that Haeberlen is occasionally presented as (∆δη), however the (ζη) definition is far more common). Two less practiced conventions are used as well. The Axiality/Rhombicity (AxRh) convention is sometimes used in spin dynamics and spin relaxation theory as the parameters come from the irreducible spherical tensor expansion of an interaction Hamiltonian. In addition to the four conventions listed in Table , we also investigate learning directly on the principal axes (i.e. δ 11 , δ 22 , and δ 33 ) in the standard convention to give a total of five conventions investigated for the invariant property predictions.