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Seminar 4/18/2012 - Dudley Herschbach, Harvard University: Dimensional Scaling in Chemical Physics

Abstract: Dimensional scaling tames dynamical correlations among strongly  interacting particles by introducing a D-dependent length unit which serves to remove the major, generic D-dependence of the quantity to be determined. Often the scaled quantity can be evaluated at one or more special D-values, where the computation becomes relatively easy. Then an approximation for D = 3 can be obtained by relating it to the special D-values, usually by interpolation or a perturbation expansion in 1/D.  Examples treated include: shapes of random walks, equation of state for hard-sphere fluids, and electron correlation in atoms. An analytic large-D approximation for N-electron atoms enables a simple renormalization method to provide good estimates of correlation energies and suggests prospects to enhance density functional theory.  D-scaling permits computing quantum tunneling by purely classical means and also reveals hidden symmetries and phase transitions involved in electronic structure of atoms and molecules. 

Bio: Third-generation native of San Jose, California. Grew up near Cupertino, in what was then rural area; for years milked cows, fed chickens and pigs, picked prunes, apricots, and walnuts in summers. First in his family to attend college, recruited as a football player. Earned B.S. in math (1954) and M.S. in chemistry at Stanford, mentored by George Polya and Harold Johnston; A.M. in physics and Ph.D. in chemical physics (1958) from Harvard, mentored by E. Bright Wilson.  Junior Fellow, Harvard (1957-59).  Asst & Assoc professor at U.C. Berkeley (1959-63), undertook experiments to probe reaction dynamics of molecules in single collisions.  Returned to Harvard in 1963.  With Yuan Lee and John Polanyi, shared Nobel Prize in 1986. Taught graduate courses in quantum mechanics, molecular spectroscopy, and collision theory; undergrad courses in physical chemistry and for twenty years freshman chemistry, his most challenging assignment.

Emeritus at Harvard since 2003, have continued since to teach freshman seminar (“Molecular Motors: Wizards of the Nanoworld”) there; also have visiting appointments in physics and chemistry at Texas A & M University (since 2005) and at the geophysical laboratory at the Carnegie Institution of Washington. Current research topics: unorthodox dimensional scaling approach to electronic structure; elucidating interaction of molecules with superintense laser fields; analysis of wave function entanglement that pertains to proposed quantum computers.

All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.

Location: Bowen Hall Auditorium

Date/Time: 04/18/12 at 12:00 pm - 04/18/12 at 1:00 pm

Category: PRISM/PCCM Seminar Series

Department: PRISM