9306375 Straub John Straub is funded by a grant from the Theoretical and Computational Chemistry Program to develop new algorithms for performing many-body classical dynamics and global energy optimization. He has recast the classical molecular dynamics problem into a Liouville operator which operates on a time dependent phase space distribution represented by a Hartree product of Gaussian wave packets. The result is a set of simple first order equations of motion for the approximate time-dependence of the distribution at contant temperature or energy. This methodology will be applied to studies of the dynamics of atoms or molecules on surfaces, the simulation of molecular fluids and biomolecules, and enhanced free energy perturbation calculations. In a second but related area of study, Straub will develop a method for finding the global energy minimum on a potential energy surface through an approximate solution to the Schrodinger equation in imaginary time. %%% Computer simulations have provided a number of molecular level insights into chemical processes which occur in solution and on surfaces. The technique is very powerful, but is limited by statistical sampling problems associated with the speed of current supercomputers and the time available to perform such simulations. Straub is developing a new algorithm for performing molecular simulations which should be a major improvement in statistical sampling. If successful, this new algorithm could provide a significant decrease in the amount of computational resources required to obtain meaningful sampling statistics in molecular simulations. ***
