Walter Kohn is an Austrian-born American theoretical physicist. He was born on  March 9, 1923 in Vienna, Austria. After earning Bachelor’s and Master’s degrees from the University of Toronto in 1946, Kohn received his Ph.D. in Nuclear Physics and a postdoctoral fellowship with Julian Schwinger at Harvard University in 1948. He was awarded, with John Pople, the Nobel Prize in chemistry in 1998. The award recognized their contributions to the understandings of the electronic properties of materials. Kohn played the leading role in the development of density functional theory, which made it possible to incorporate quantum mechanical effects in the electronic density. This computational simplification led to many insights and became an essential tool for electronic materials, atomic and molecular structure. In 1988, he received the National Medal Of Science.