In science our impact is regularly measured by citation metrics and awards (among others), and there is no doubt that Axel was one of the all-time superstars in this respect. Less measurable, but even more important, is the impact we have on our colleagues and students that surround us. I believe Axel had a profoundly positive impact on the people around him, and I hope to spend my time in this presentation sharing some stories that reflect that.

I had the good fortune to be Axel's Postdoc from 2017-2019. This position with Axel allowed me to continue working on a DFT problem I had developed a fascination with, delocalisation error. Specifically, we revisited his B05 functional to show that it is capable of addressing some of the problems caused by delocalisation error.

This presentation will share samplings of the research profile I have developed since leaving his group. Highlights of these research topics will be: \begin{itemize} \item a new differentiable DFT program developed which hopes to address the difficulties of implementing a B05 convergence algorithm. \item new results on delocalisation errors and pitfalls to avoid. \item a new transition state searching algorithm. \end{itemize}