He is the inaugural Sir Alan Cottrell Professor of Materials Science in the Department of Materials Science and Metallurgy, University of Cambridge. Previously he was Professor of Physics, University College London, and Reader in Physics, University of St Andrews. He has held EPSRC Advanced and Leadership Research Fellowships, and a Royal Society Wolfson Research Merit Award. He is a lead developer of the widely used CASTEP computer code, and introduced both the GIPAW approach to the prediction of magnetic resonance parameters and Ab Initio Random Structure Searching (AIRSS). CASTEP has provided a significant source of licencing income for Cambridge Enterprise for over 20 years, while his AIRSS software is free available through an open-source license. In 2015 he won the Rayleigh Medal and Prize of the Institute of Physics, awarded for distinguished research in theoretical, mathematical or computational physics.