Robert S. Mulliken

Robert Sanderson Mulliken (June 7, 1896 to October 31, 1986) was an American physical chemist born in Newburyport, Massachusetts, who died in Arlington County, Virginia. He won the 1966 Nobel Prize in Chemistry for developing molecular orbital theory, a framework that describes electrons as belonging to the molecule as a whole rather than to bonds between specific atom pairs. This approach, worked out largely at the University of Chicago, gradually superseded the competing valence bond picture and became the standard language for describing chemical bonding and molecular structure across chemistry.