Chemistry Nobel Laureate Walter Kohn died April 19. He was 93. An emeritus professor of physics at the University of California, Santa Barbara, he received the Nobel Prize in 1998 for his development of density functional theory.
Kohn’s work established the theoretical underpinnings of density functional theory, which is widely used for computational studies in chemistry, physics, and materials science. In 1964, working with Pierre Hohenberg, Kohn proved that the ground state electron density of a molecule exactly specifies that molecule’s total energy and all its ground state properties. The following year, working with Lu Sham, he developed a procedure for solving density functional theory equations.
“The work of Walter Kohn had a huge impact on the field of chemistry in at least two ways,” says Gregory A. Voth, a theoretical chemist at the University of Chicago. “First, electronic density functional theory has arguably become the most widely used electronic structure method in all areas of chemistry.” Second, Voth says, Kohn showed that for each molecular system a “true” electronic density functional must exist. In doing so, Voth says, Kohn set off a search that “has been the focus of countless theoretical chemists and is likely to continue be so for many years to come.”
Kohn was born to a Jewish family in Vienna, Austria, in 1923. His parents died at Auschwitz during the Holocaust, but he and his sister managed to escape. He immigrated to England in 1939. From there, he was sent to a refugee camp in Canada in 1940. He received his bachelor’s degree in math and physics in 1945 and his master’s degree in applied mathematics in 1946, both from the University of Toronto. In 1948, he received his Ph.D. in physics from Harvard University. He became an American citizen in 1957.
Kohn was a physics professor at Carnegie Mellon University from 1950 to 1960. In 1960, he moved to the University of California, San Diego. In 1979, he moved to UC Santa Barbara to serve as the founding director of the Institute for Theoretical Physics, which is now the Kavli Institute for Theoretical Physics. He had been an emeritus professor since 1991.
“Walter was an internationally regarded colleague, scholar, mentor, and role model, and, proudly, the first of six Nobel Laureates at UC Santa Barbara since 1998,” says Henry T. Yang, chancellor of UCSB. “His development of the density functional theory, for which he received the Nobel Prize in Chemistry, revolutionized scientists’ approach to the electronic structure of atoms, molecules, and solid materials in physics, chemistry, and materials science.”