O Oct. 13, 1998, Walter Kohn of the University of California at Santa Barbara was awarded the 1998 Nobel Prize in Chemistry for his development of the density-functional theory.

Kohn showed that it is not necessary to consider the motion of each individual electron: it suffices to know the average number of electrons located at any one point in space. This has led to a computationally simpler method, the density-functional theory. The simplicity of the method makes it possible to study very large molecules.