Robert S. Mulliken

Robert Sanderson Mulliken was born June 7, 1896, and trained as an American physical chemist at a moment when the quantum revolution was rewriting the rules of matter. He devoted himself to molecular orbital theory, developing the method that computes molecular structure not by classical bonds but by the behavior of electrons across entire molecules. The elaboration was painstaking, mathematical, and it worked. He received the Nobel Prize in Chemistry in 1966, then the Priestley Medal in 1983. He died October 31, 1986, having given chemistry a language it still speaks.