Seminars & Events

Argonne Leadership Computing Facility
"Forward-Backward Semiclassical and Quantum Dynamics"

DATE: April 16, 2010
TIME: 10:30 AM - 11:30 AM
SPEAKER: Jonathan Chen, Ph.D. Candidate, University of Illinois at Urbana-Champaign
LOCATION: Building 240 / Conference Room 4301, Argonne National Labortory

Description:
The forward-backward semiclassical dynamics (FBSD) method alleviates the notorious quantum dynamical sign problem through pre-cancellation of the forward and backward classical action integrals; the resulting quasiclassical scheme has been applied successfully to condensed phase systems as quantum mechanical as superfluid helium. Recent developments in FBSD have accelerated convergence with respect to the number of imaginary time steps; applications to model anharmonic systems and Lennard-Jones fluids will be discussed.

Bailey's generalization of Hamilton's principle of stationary action has been used to solve Bohm’s hydrodynamic equations of motion in the forward-backward quantum dynamics (FBQD) formulation of time correlation functions, yielding the first reported stable, synthetic calculation of quantum trajectories for the one-dimensional quartic oscillator at zero and low temperatures. Interestingly, accuracy and stability vary more with asymmetry than anharmonicity.

FBSD references
N. Makri, A. Nakayama and N. Wright, J. Theor. Comp. Chem. 3, 391-417 (2004).
A. Nakayama and N. Makri, Proc. Nat. Acad. Sci. U.S.A. 102, 4230-4234 (2005).
J. Chen and N. Makri, Mol. Phys. 106, 443-453 (2008).

FBQD references
N. Makri, J. Phys. Chem. 108, 806-812 (2004).
J. Chen and N. Makri, J. Chem. Phys. 131, 124107 (2009).
J. Chen and N. Makri, Chem. Phys. (2010), in press.

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