KOHN, WALTER

KOHN, WALTER (1923– ), U.S. physicist and Nobel laureate. Kohn was born in Vienna where he attended the Akademische Gymnasium. He moved to the Jewish Chajes Gymnasium where he received exceptional teaching in mathematics from Dr. Victor Sabbath and in physics from Dr. Emil Nohel, both of whom perished in the Holocaust. After the Nazi annexation of Austria, he reached England on the kindertransport   in August 1939 but left for Canada in July 1940. After periods of internment in both countries of refuge he graduated and next received his master's degree in mathematics and physics at the University of Toronto in shortened courses interrupted by service in the Canadian Army (1941–46). He gained his Ph.D. from Harvard University for work on variational principles under the guidance of Julian Schwinger (1948). He was a fellow in Schwinger's department (1948–50) followed by an initial period at the Carnegie Institute of Technology in Pittsburgh (1949–51) before he went as a visiting research worker to Niels Bohr's laboratory at the Institute of Experimental Physics in Copenhagen on a National Research Council Fellowship (1951–52). He returned as professor to the Carnegie and regular collaboration with Bell Laboratories (1952–60) before moving to the University of California at San Diego (1960–79). He then moved to the University of California at Santa Barbara, initially to direct the National Science Foundation's Institute for Theoretical Physics (1979–84) and subsequently as professor of physics (1984–91), where he became emeritus research professor. Kohn developed mathematical models and computational techniques for applying quantum mechanics to chemistry. His density functional theory based on electrons' spatial distribution made it possible to describe the bonding of atoms and thereby to study the structure and function of complex molecules. These principles are now used universally. He remained active in that field. He was awarded the Nobel Prize for chemistry (1998) jointly with John Pople. His other honors include the National Medal of Science (1988), the UNESCO Gold Medal (1998), fellowship of the U.S. Academy of Sciences, and foreign membership of the Royal Society of London. He was a visiting professor at the Hebrew University of Jerusalem (1970) and a member of the Board of Governors of the Weizmann Institute from 1996. He also had a sustained interest in the Pugwash organization and in other world issues such as population pressure on resources. The father of his second wife, Mara, was Roman Vishniac, the noted photographer of Eastern Europe. (Michael Denman (2nd ed.)