Jemmis is professor of chemistry at IISc, Bangalore. He studies the structure and reactivity problems of real life molecules, clusters and solids using theoretical techniques. He has successfully linked different areas of chemistry through his computational chemical approach. His major contributions include theoretical study of transition metal complexes of fullerenes and their ring-opened alternatives; a unifying electron-counting rule for polyhedral boranes, metallaboranes, and metallocenes; electronic structural requirements for macro-polyhedral boranes and elemental boron; establishment of novel analogies between carbon and boron, and on the structures and reactions of transition metal organometallics. He is a fellow of all science academies of India, winner of the INSA Young Scientist Prize, SS Bhatnagar Prize, Millennium Medal of Indian CSIR and other national science honours. Govt of India honored him with the civilian award, Padma Shri.