Michael J. S. Dewar was a pioneering theoretical chemist whose work fundamentally transformed computational organic chemistry. Born in Ahmednagar, India in 1918, he began his distinguished academic career at Queen Mary College, University of London in 1951 before moving to the University of Chicago in 1959. He then established himself as a leading figure in theoretical chemistry when he accepted the first Robert A. Welch research chair at the University of Texas at Austin in 1963, where he transformed the department into a global center for theoretical chemistry. In 1989, he moved to the University of Florida, continuing his groundbreaking research until his retirement in 1994 as Professor Emeritus.
Dewar is most renowned for developing the semi-empirical quantum chemistry methods MINDO, MNDO, AM1, and PM3 that formed the basis of the MOPAC computer program, enabling quantitative study of large molecular systems for the first time. His early work in the 1950s established the molecular orbital theory of organic chemistry, extending Erich Hückel's quantum mechanical treatments through perturbation theory and resonance theory. These computational methods revolutionized theoretical chemistry by allowing scientists to study reaction mechanisms and molecular structures that were previously intractable. The widespread adoption of his methodologies laid the foundation for modern computational chemistry, with applications spanning drug discovery, materials science, and chemical engineering.
Dewar's intellectual leadership attracted numerous international scholars to his research groups, fostering a generation of theoretical chemists who continue to advance the field. His more than fifty doctoral students and six postdoctoral fellows carried his innovative approaches to institutions worldwide, amplifying his scientific influence. Recognized with prestigious honors including membership in the National Academy of Sciences and the Davy Medal, Dewar's legacy endures through the continued use of his computational methods and the theoretical frameworks he established. His work remains foundational to contemporary computational chemistry, with modern implementations building directly upon his pioneering semi-empirical approaches.
