In late 2024, Dr. Simon León Krug completed his PhD at TU Berlin summa cum laude with a thesis on "Relative and Systematic Methods in Computational Alchemy"—a field that examines how molecular properties change when atoms are substituted. His doctoral research began at the University of Vienna and later continued in the Machine Learning Group at BIFOLD under the supervision of O. Anatole von Lilienfeld and Klaus-Robert Müller.
Simon's work sits at the intersection of theoretical chemistry, quantum physics, and machine learning. He is particularly drawn to the mathematical structures underlying scientific theories—especially integrals and their transformations. Since January 2025, he is a postdoctoral researcher at ETH Zurich, where he now explores chemical kinetics and the optimization of dye-sensitized solar cells.
Please describe and explain your research focus?
Simon: My research focuses on computational alchemy, which, despite sounding esoteric, is an established method in computational chemistry. While computational chemistry often explores how a molecule’s properties change when the number of electrons is altered, computational alchemy asks the reverse: what happens to those properties when the number of electrons stays the same, but atoms are replaced with others? For instance, since both carbon monoxide (CO) and dinitrogen (N₂) have 14 electrons, computational alchemy can be used to predict the properties of CO based on those of N₂—though these are distinct molecules to a chemist. I particularly enjoyed this work because it combined mathematical analysis, especially integral transforms, programming, and the opportunity to apply quantum-mechanical models enhanced by machine learning.
Which major innovation do you expect in your research field in the next ten years?
Simon: A major innovation will be basis sets that allow for smooth interpolation between nuclear charges. Basis sets are mathematical tools that describe electron distribution in molecules. Such tools would enable more continuous and flexible simulations of computational alchemy.
What personally motivated you to enter an academic research career?
Simon: Initially, I had planned to leave academia after my master's degree. However, during spring and summer of 2020, I witnessed many friends struggle with their entries into professional life, such that I found myself applying for PhDs as a 'safety net.' Only during my last year as a doctoral student did I consider research as a viable career to be worth pursuing.
What are your recent projects?
Simon: My postdoc has led me to a fascinating area of study-chemical kinetics, the prediction of chemical reaction rates. One of the most exciting aspects of our current research is the potential to significantly enhance so-called dye-sensitized solar cells by adding adequate compounds. I am truly passionate about understanding the factors that drive these photoconversions and identifying the most promising molecules.
Which living or historical scientist has fascinated you and why?
Simon: Hermann Graßmann (1809 – 1877) - because he lived during a politically and scientifically exciting time. His work was a precursor to many concepts ubiquitous in mathematics today. I want to be as creative as him and my work to be as useful as his.
AI is considered a disruptive technology - in which areas of life do you expect the greatest upheaval in the next ten years?
Simon: I expect it to take over many simple or repetitive tasks in the next ten years. Primarily for reasons of cost-efficiency and reliability, especially in our achievement-oriented society. However, I believe that in many service-oriented professions, people will increasingly realize that the value of a service is not only in its outcome but also in who provides it. This contrast—between automation for efficiency and the human element in service—will likely lead to growing social tensions.
Where would one find you if you were not sitting in front of the computer?
Simon: In the kitchen, preparing fruit pies or bread. The pies because I enjoy baking, and the bread because I have yet to find a satisfying sourdough bakery in Zürich.