News

Dr Martin Stöhr wins Rolf Tarrach Prize 2022

  • Faculté des Sciences, des Technologies et de Médecine (FSTM)
    Université / Administration centrale et Rectorat
    13 juillet 2022
  • Catégorie
    Recherche, Université
  • Thème
    Physique & sciences des matériaux

The 2022 award for the best PhD thesis of the University of Luxembourg was conferred to Dr Martin Stöhr, PhD in Physics, for his work “Van der Waals Dispersion Interactions in Biomolecular Systems: Quantum-mechanical Insights and Methodological Advances”, under the supervision of Prof. Dr Alexandre Tkatchenko. 

The work focuses on computational modelling which today has become an integral part of chemistry, biology and materials science. It plays a key role in a wide range of developments, from drug design to next generation catalysts and energy materials.

On a macroscopic scale, systems can be described by classical mechanics. Below that, at the level of atoms and molecules, the behavior and properties of matter follow the laws of quantum mechanics. While the governing laws are known, the application of these laws require equations that are hard to solve.

Various developments have led to approximate methods for solving these equations. However, the more sophisticated and reliable any given method is, the more steeply the computational workload increases in relation to the size of the system to be studied. Despite the tremendous growth in the availability of high-performance computing resources, this still limits he most accurate theories to rather small systems.

To study phenomena at increasing length and time scales, scientists resort to approximate approaches, extrapolating from smaller to larger systems. However, practically relevant systems, such as proteins or energy materials and catalyst systems are naturally of nano-scale size and therefore small enough not to be adequately described by classical physics, but at the same large enough for complex many-body quantum effects to cause decisive deviations from the well-studied behaviours of few-particle quantum systems.

Identifying such deviations, potential shortcomings of conventional approximations, and developing efficient solutions is paramount for the reliable description of phenomena in practically relevant systems.

The goal of Dr Martin Stöhr’s research work is to gain such fundamental understanding and accurate description of nano-scale systems in realistic settings. To this end, he developed new methodological approaches and analysis tools; combined with high-performance implementations, they enable the description and understanding of large-scale systems in so far unmatched detail, going beyond the assumptions of conventional, more approximate methods.

In its report on the defence of Dr Stöhr’s thesis submitted in 2020, the thesis jury states that “the candidate has successfully developed a range of conceptual advances and computational methods that go significantly beyond the state of the art”. The jury also estimated Dr Stöhr’s scientific achievements to be “a real break-through in the modelling of dispersion interactions in large and complex systems” and judged the thesis to be “extraordinarily broad, ranging from contributions to the fundamental physical understanding of macromolecular systems, over highly complex applications to protein systems, [to] substantial method development in the area of computational physics and machine learning.”

Q: Martin Stöhr, your research work harbours the potential to improve the accuracy of modelling the interactions in large systems with thousands of atoms. Can you give us an idea of the potential applications this could or can have?

A: Precisely. The main goal of my research is to push the applicability of accurate theories in chemical physics towards realistic and practically-relevant systems. Especially in the context of biomolecules this involves large-scale simulations.

Being able to describe and conceptually understand the emergent phenomena in such systems allows us to decipher how living organisms function on a basic level. Only once we understand in detail how a process works, can we address remedies in case it doesn’t; or limit it in the case of malign processes like tumor growth or virus infections.

One key advantage of theoretical computational methods is then the ability for example to screen thousands of potential drug candidates — many more than could ever be tested in experiment and long before even touching a living organism, thereby avoiding potentially harmful effects in the early stages of drug design. From a different perspective, nature has come up with stunning, highly optimised processes after having evolved for millions of years. Understanding these fundamental processes allows to mimic them in technological applications in the form of molecular machines or artificial enzymes as highly selective and efficient catalysts. For both fields of application, medicinal and technological, my research efforts provide two key parts: the in-depth understanding necessary to design new compounds and the simulation techniques to test them.

Q: What made you choose this particular topic of research? Any particular trigger?

A: Interestingly enough, my main research project initially only started as a side project. Soon after the first discussions on the topic, however, I was convinced of the vast opportunities of using expertise from theoretical and computational chemistry to advance biomolecular simulations. Hence, bridging the gap between fundamental quantum-mechanical modelling and practically-relevant applications to eventually address real-world problems was a major motivation for my choice. Another aspect was the interdisciplinarity of the project. I was quickly caught by the prospect of exploring various fields across physics, chemistry, biology, and high-performance computing instead of focusing on one rather narrow topic during my PhD.

Q: What recommendation would you give a PhD candidate starting on their thesis work today?

A: My main advice would be to be ambitious but to not expect to solve everything all at once. Research can seem incremental in the bigger breakthroughs, and achievements only become apparent afterwards. Also, I can only recommend to branch out and discuss with experts from different areas of research, because very often ideas from one field can help solve crucial problems in others. Science is a community effort and embracing this makes it so much more enjoyable.

Martin Stöhr: Abstract of PhD Research “van der Waals Dispersion Interactions in Biomolecular Systems: Quantum-mechanical Insights and Methodological Advances

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