Professor Emeritus Hans C. Andersen applies statistical mechanics to develop theoretical understanding of the structure and dynamics of liquids and new computer simulation methods to aid in these studies.
He was born in 1941 in Brooklyn, New York. He studied chemistry as an undergraduate, then physical chemistry as a doctoral candidate at the Massachusetts Institute of Technology (B.S. 1962, Ph.D. 1966). At MIT he first learned about using a combination of mathematical techniques and the ideas of statistical mechanics to investigate problems of chemical and physical interest. This has been the focus of his research ever since. He joined the Stanford Department of Chemistry as Assistant Professor in 1968, and became Professor of Chemistry in 1980. He was named David Mulvane Ehrsam and Edward Curtis Franklin Professor in Chemistry in 1994. Professor Andersen served as department chairman from 2002 through 2005. Among many honors, his work has been recognized in the Theoretical Chemistry Award and Hildebrand Award in Theoretical and Experimental Chemistry of Liquids from the American Chemical Society, as well as the Dean's Award for Distinguished Teaching and Walter J. Gores Award for Excellence in Teaching at Stanford. He has been elected a member of the National Academy of Sciences, and a fellow of both the American Academy of Arts and Sciences and American Association for the Advancement of Science.
Professor Andersen’s research program has used both traditional statistical mechanical theory and molecular dynamics computer simulation. Early in his career, he was one of the developers of what has come to be known as the Weeks-Chandler-Andersen theory of liquids, which is a way of understanding the structure, thermodynamics, and dynamics of simple dense liquids. Later, he developed several new simulation techniques – now in common use – for exploring the behavior of liquids, such as simulation of a system under constant pressure and/or temperature. He used computer simulations of normal and supercooled liquids to study the temperature dependence of molecular motion in liquids, crystallization in supercooled liquids, and the structure of amorphous solids.
Professor Andersen also developed and analyzed a class of simple lattice models, called facilitated kinetic Ising models, which were then widely used by others to provide insight into the dynamics of real liquids. He simulated simple models of rigid rod polymers to understand the dynamics of this type of material. More recently, in collaboration with Professor Greg Voth of the University of Chicago, he has applied statistical mechanical ideas to the development of coarse grained models of liquids and biomolecules. Such models can be used to simulate molecular systems on long time scales. He has also used mode coupling theory to describe and interpret experiments on rotational relaxation in supercooled liquids and nematogens, in collaboration with Professor Michael Fayer of the Stanford Chemistry Department.