Richard Catlow, Fellow of the Royal Society, has been involved for over 20 years in capacity building initiatives in Africa, including currently a Royal Society/Leverhulme project in Ghana and a Royal Society/DFID project involving Ghana, Botswana and Namibia. He has served on the Royal Society Africa Exchanges Committee and the Royal Society DfID Africa Capacity Building Initiative Panel. Professor Catlow is developing and applying computer models to solid state and materials chemistry — areas of chemistry that investigate the synthesis, structure and properties of materials in the solid phase. By combining his powerful computational methods with experiments, he has made considerable contributions to areas as diverse as catalysis and mineralogy. His approach has also advanced our understanding of how defects — missing or extra atoms — in the structure of solids can result in non-stoichiometric compounds. Such compounds have special electrical or chemical properties since their contributing elements are present in slightly different proportions to those predicted by chemical formula.