Department of Chemistry
University of California at Berkeley
“Path Integrals Simulations in Chemistry”
Tuesday, February 13, 2007
Chemistry Building, Room 412
Abstract: Path integrals represent the starting point for many of the techniques that one day could enable unbiased investigation of non-trivial quantum effects in complex systems as well as direct sampling of transition paths for systems driven by stochastic dynamics. To date, the simulation techniques available are rarely up to the task of providing quantitative answers on par with what molecular dynamics or Monte Carlo methods can achieve for classical systems. Perhaps surprisingly to many, even basic thermodynamic quantities such as partition functions, average energies or heat capacities are difficult to obtain. The causes are multiple and can be related to the inadequacy of the estimators, the short-time approximations employed, and the Monte Carlo sampling techniques. I shall discuss the recent contributions of the present author to each of these areas. Non-trivial examples are provided by the computation of partition functions of an 18-atom catalytic system employed for methane oxidation and unexpected structural changes caused by quantum effects in the Ne38 cluster.