Robert S. Mulliken's early interests and education were in the field of chemistry, especially in the structure of molecules. He eventually discovered that quantum mechanical theory offered an effective tool for the study of the topic and switched his allegiance to the field of physics, a subject that he taught for more than three decades at various institutions. His work ultimately contributed to the establishment of a new interdisciplinary subject, combining these two great fields of science in what is known as chemical physics. Mulliken's research has led to a new understanding of the way in which atoms are held together in molecules and the ways in which molecules interact with each other. In recognition of these accomplishments, he was awarded the 1966 Nobel Prize in chemistry.

Robert Sanderson Mulliken was born in Newburyport, Massachusetts, on June 7, 1896. His father was Samuel Parsons Mulliken, a professor of organic chemistry at...