Dumitru-Claudiu Sergentu, computational chemist, building tools for the rational design of molecular magnets

Dr Dumitru-Claudiu Sergentu is a computational chemist working on the rational design of single molecule magnets thorough combined model and effective Hamiltonian approaches. He implements the “NewMag” project at the ISCR laboratory, University of Rennes.

BIENVENÜE team: Hello Claudiu, how did you become interested in computational chemistry?

Dr Sergentu: By completing a bachelor’s degree in physical chemistry, I developed a passion for chemistry, math, and computer science. I then decided to delve more into the use of computers in chemistry, and I embarked on a European Erasmus-Mundus master’s program at the University of Groningen, The Netherlands, studying full-time theoretical chemistry and computational modelling. There, trained by international experts in the field, I quickly became fascinated by how much chemistry we can do simply by using computers, without the burden of running a real laboratory. My master’s thesis project turned into my first published article, and my master’s colloquium, a literature survey required to graduate, marked the debut of my doctorate in theoretical and computational chemistry, which I defended in 2016 at the Université de Nantes. During my PhD, I worked closely with experimentalists to advance efficient computational tools for studying the fundamental chemistry of astatine, a radioelement of particular interest for cancer treatment in targeted radioimmunotherapy.

From 2017 to 2021, I was in the USA, at SUNY Buffalo, where I conducted research on the electronic structure and magnetic properties of some of the heaviest elements in the periodic table, namely the actinides. This period marked my growth in the field of computational chemistry and gave me the confidence to pursue my own project. I learned about the BIENVENÜE opportunity from my current supervisors, Dr. Rémi Maurice and Dr. Boris Le Guennic, and made the decision to return to France.

What will you investigate during the NewMag project?

My project, NewMag, aims toward the rational design of single-molecule magnets (SMMs), a class of tiny magnets that serve as building blocks in molecular spintronics, intelligent sensors, and the next generation of storage devices, among others. These technologies act at the level of the electron spin and harness information from the orientation of these spins in certain conditions. However, projecting SMMs for technological applications still requires extensive fundamental research on their behaviour at the level of atoms and electrons. Additionally, novel computational strategies and tools derived from quantum mechanics, the theory that rules the behaviour of tiny particles, are needed to facilitate progress. This is the end goal of NewMag, to provide experimentalists with a simple yet powerful quantum-mechanical framework that can assist in the rational design of future SMMs.

Which impact can have your work in everyday life?

The engineering of tiny molecules with record magnetic properties plays a crucial role in the future of smart technologies. For instance, it is sufficient to take a look at what has happened with our storage devices over the last decades. In the 1950s, we started off with hard disk drives (HDDs) the size of a refrigerator. Nowadays, we have HDDs and newer-generation solid-state drives (SSDs) that are no larger than 2.5 or 3.5 inches, in addition to little flash drives and microSD cards providing substantial storage capacity to our computers and smartphones. As data is generated today at a scale larger than ever before, there is naturally high demand for miniaturized memory devices with high storage capacity and more secure read-write capabilities. In this regard, SMMs offer high-density storage, energy efficiency, enhanced stability against external stimuli when appropriately engineered, and the ability to retain magnetic memory over long periods of time. My work plays a crucial role in advancing our understanding of the behaviour of new, small molecules with SMM characteristics by providing the necessary tools and a framework for interpreting experimental data. This contribution is significant as it aligns with the future prospects of SMM-based memories.

Why the ISCR lab is a good place to conduct this project?

The CTI team, with whom I am affiliated at the ISCR Institute of the University of Rennes, has a long-standing history of research and innovation in the field of chemical spectroscopy and magnetism. The team actively participates in European collaborations and possesses a state-of-the-art hardware and software infrastructure that facilitates quantum chemistry research on small molecules, biomolecules, and extended materials. Most importantly, here at the ISCR, the NewMag project is fortunate to have the supervision of two highly qualified scientists in the field of magnetism and single-molecule magnet research, Dr. Rémi Maurice and Dr. Boris Le Guennic.