ACTIONS 1999INTERACTIONS 1999
1998 Nobel Prize
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| Walter Kohn | John Pople |
Two former Carnegie Mellon professors were awarded the 1998 Nobel Prize in Chemistry. Walter Kohn was in the Physics Department from 1950 to 1960. He then moved to the University of California at San Diego where his award-winning work was performed. Since 1979 he has worked at the Center for Theoretical Physics in Santa Barbara. John Pople was a professor in the Chemistry Department from 1964 to 1986 at which time he moved to Northwestern University.
| The Nobel Prize citation reads "to Walter Kohn for his development of the density-functional theory and to John Pople for his development of computational methods in quantum chemistry." Both researchers showed how quantum mechanics could be employed to calculate the bonding of atoms in solids and molecules. The problem was challenging because the electrons orbiting the atoms repel each other strongly due to their negative charge. To under-stand the interactions of atoms it might seem like one must solve for the detailed motion of every electron in the presence of every other electron. Walter Kohn showed that the electronic ground state energy actually depends only on the spatially varying density of electrons and does not require knowing the details of individual electron trajectories. John Pople developed a computer program called GAUSSIAN that greatly reduced the computer time needed to perform accurate calculations including electron interactions. Today, methods pioneered by these researchers are used to solve a wide variety of problems such as modeling the structure of crystals, predicting the dynamics of chemical reactions and designing drugs to fight disease. | 
The electron density around the vitamin C molecule. |
Pople’s computer systems were run in conjunction with the Physics Department’s facilities and housed in Wean Hall. One DEC computer carried a plaque reading "The First VAX 11/780 Representing Digital’s Continuing Commitment to Science." The need for continuing improvement of this computing facility led eventually to the founding of the Pittsburgh Supercomputer Center with support from the National Science Foundation.
Kohn and Pople both received honorary degrees at Carnegie Mellon’s spring 1999 graduation.
