In 1983, the the American Chemical Society awarded the Priestley Medal to Robert S. Mulliken ‘for his numerous contributions to chemistry,” the Society’s most prestigious award.

Mulliken, from the University of Chicago, is best known for his work in developing the molecular orbital theory of molecular structure. He is best known for his work in developing the molecular orbital theory of molecular structure. His research into valence theory and molecular structure, earned him the nickname “Mr. Molecule.”