  Many chemical concepts can be well defined in the context of quantum chemical
theories. Examples are the electronegativity scale of Mulliken and Jaffe and
the hard and soft acids and bases concept of Pearson. The sound theoretical
basis allows for a systematic definition of such concepts. However, while they
are often used to describe and compare chemical processes in terms of
reactivity, their predictive power remains unclear. In this work, we elaborate
on the predictive potential of chemical reactivity concepts, which can be
crucial for autonomous reaction exploration protocols to guide them by
first-principles heuristics that expoit these concepts.
