Professor Stewart Clark

Professor in the Department of Physics

What do you do?

I am a Professor of Physics at Durham University, specialising in computational and theoretical condensed matter physics. When not teaching, my research focuses on the development and application of electronic structure methods, an area of applied quantum mechanics, to explore the properties of complex materials.

I am an author of the CASTEP code, a leading tool in electronic structure calculations, and have published extensively in this field. I actively collaborate with industry and academia to drive theoretical quantum mechanics through to technological innovations.

How are you involved in this area of science? 

My research in quantum mechanics focuses on electronic structure, which is key to understanding the behaviour of materials. Since the properties of materials are fundamentally determined by the actions of their electrons, knowing how electrons behave allows me to predict and explain material properties. This is crucial for designing new technologies, such as semiconductors, magnets, pharmaceuticals, and LEDs—items now integral to everyday life.

I develop computational algorithms that apply quantum mechanical principles, which cannot be solved analytically, to model and predict electron behaviour. This I program into a code that I author called CASTEP. These algorithms solve the equations governing electrons, enabling me to extract material properties. The results are used to interpret experimental data, predict novel materials, and guide technological applications across a wide range of fields.

What do you love about this topic?

In quantum mechanics and electronic structure I love the challenge of unlocking the mysteries of how materials behave at the atomic level. The excitement of turning complex, unsolvable equations into computational models that reveal the inner workings of materials is very rewarding.

I've always liked computer programming as it allows me to turn physics and maths into something I enjoy. The ability to predict new materials and see their potential applications in cutting-edge technology, from semiconductors to pharmaceuticals, offers a sense of discovery and impact.

How does this work deliver real-world impact?

By programming my research into CASTEP, a code for simulating the properties of materials, I help deliver real-world impact across both academia and industry. CASTEP enables researchers to model and predict the behaviour of materials at the atomic level, guiding the development of new technologies in sectors such as electronics, energy, and pharmaceuticals. It allows academic scientists to advance fundamental research, while industry partners use it to design materials with specific properties, improving product performance and efficiency. This collaboration between theory and application accelerates innovation, leading to breakthroughs in semiconductors, renewable energy materials, and other cutting-edge technologies.