个人简介
M.S., Physics, 1992, Moscow Institute of Physics and Technology
Ph.D., 1999, University of Notre Dame
Postdoctoral Fellow, 1999-2001, University of Chicago
USC Rising Star 2012
Doctoral New Investigator ACS-PRF 2011
NSF:Career 2011
IBM-Lowdin Fellowship, Sanibel symposium 2004
研究领域
Physical
Theoretical and computational chemistry focusing on quantum effects in dynamics of nuclei, development of approximate quantum trajectory dynamics method scalable to large molecular systems, incorporation of the zero-point energy, quantum tunneling, and other quantum effects in reactive dynamics, i. e. into proton transfer processes.
Quantum effects in dynamics of nuclei Quantum-mechanical effects in molecular dynamics are essential for accurate description and understanding of many chemical processes, such as those in surface reactions, photochemistry, in interactions of molecules with electric field, in chemistry of polymers, clusters and liquids. QM effects are the most pronounced in processes involving atomic and molecular hydrogen including reactions in enzymes, other biomolecular environments and nanomaterials. For example the isotope effects in water are manifested in such basic properties as melting point, which is 3.82C for deuterated water, and the temperature of maximum density in liquid state, which is 4C for water and 11.2C for deuterated water. Both issues can be resolved by doing dynamics simulation with quantum trajectories. Our theoretical work is guided by the ultimate goal -- to study dynamics of complex molecular systems using an accurate and efficient method which incorporates the quantum effects and is compatible with classical molecular dynamics. Possible applications include proton transfer processes in enzymes and other biomolecular environments and incoherent electron transport in open quantum systems, such as molecular electronic devices.
Quantum or Bohmian trajectories. The time-dependent Schrodinger equation can be recast in terms of the wavefunction amplitude and phase associated with the trajectories evolving in time according to Hamilton's equations of motion. All quantum effects are expressed through the action of quantum potential dependent on the amplitude and its derivatives, acting on a trajectory in addition to the external "classical'' potential. For general problems, the exact determination of the quantum potential is at least as difficult as the solution of the standard Schrodinger equation, but the quantum trajectory formulation provides a convenient starting point for approximation of the "quantum'' quantities which are small in the semiclassical limit of heavy particles such as nuclei. We develop global approximations to the quantum potential, which capture dominant quantum effects, such as zero-point energy, tunneling, wavepacket bifurcation, in a computationally efficient manner. Long-time (picoseconds) zero-point energy description is of special importance in condensed phase (system interacting with the environment). Current work extends the quantum trajectory formalism to evolution under the Boltzmann operator, which enables direct computation of thermal reaction rate constants from trajectory dynamics. High-dimensional parallel quantum trajectory code with on-the-fly force calculations (DFTB) is under development.
近期论文
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Garashchuk, S.; Jakowski, J.; Wang, L.; et al. Quantum Trajectory-Electronic Structure Approach for Exploring Nuclear Effects in the Dynamics of Nanomaterials. Journal Of Chemical Theory And Computation. Volume: 9, Issue: 12 Pages: 5221-5235 (2013).
Lahankar, S. A.; Zhang, J.; Garashchuk, S.; et al. Electronic Population Inversion in HCCO/DCCO Products from Hyperthermal Collisions of O(P-3) with HCCH/DCCD. Journal Of Physical Chemistry Letters. Volume: 4, Issue: 8 Pages: 1315-1321 (2013).
Garashchuk, S. and Volkov, M. V. Incorporation of quantum effects for selected degrees of freedom into the trajectory-based dynamics using spatial domains. Journal Of Chemical Physics. Volume: 137, Issue: 7 Article Number: 074115 (2012).
Mazzuca, J.; Garashchuk, S.; Jakowski, J. Description of proton transfer in soybean lipoxygenase-1 employing approximate quantum trajectory dynamics. Chemical Physics Letters 542, 153-158 (2012).
Garashchuk, S. Quantum trajectory dynamics in imaginary time with the momentum-dependent quantum potential. J. Chem. Phys. 132, 014112 (2010).
Rassolov, VA; Garashchuk, S; Schatz, GC. Quantum trajectory dynamics in arbitrary coordinates. Journal Of Physical Chemistry A Volume: 110, Issue: 16 Pages: 5530-5536 (2006).
Garashchuk, S. and Rassolov, VA. Energy conserving approximations to the quantum potential: Dynamics with linearized quantum force. J. Chem. Phys. 120, 1181 (2004).
Tannor, D. J. and Garashchuk, S. Semiclassical calculation of chemical reaction dynamics via wavepacket correlation functions. Annu. Rev. Phys. Chem. 51, 553 (2000).