Parallel to the evolution in modelling steric effects, the representation of electronic effects has also been further developed. Milo et al. introduced the intensity and frequency of manually selected molecular vibrations as descriptors (Figure ). For the selection of relevant vibrations, a mechanistic proposal is required a priori, commonly based on a manual analysis of the probed substrates. The inclusion of electronic parameters led to a considerable improvement in predicting the enantioselectivity of a peptide-catalysed bisphenol desymmetrisation compared to their omission,