Research

I am interested in developing practical theoretical and computational methods for modeling chemical dynamics in the condensed phase associated with energy and charge transfer in light-harvesting systems, such as photosynthetic complexes and organic photovoltaic materials. The objective is to obtain a molecular-level understanding of the fundamental processes underlying efficient energy transfer in photosynthesis that could in turn be used to harness electronic excitations in nanoscale environments. In particular, our specefic aim is to advance computational methods of quantum dynamics that can be applied to complex molecular systems. We will use the linearized path integral (LPI) approach, which provides a flexible, rigorous, and unifying platform for developing computationally feasible methods capable of capturing important quantum effects in energy and charge transfer processes, as well as molecular spectroscopy. These LPI-based methods open the door to applications to complex molecular systems, which are most naturally described by anharmonic force fields. On the contrary, traditional quantum dynamical methods that rely on treating many-body molecular systems as a bunch of harmonic oscillators cannot provide any molecular picture.

Research topics:

• Charge and Energy transfer dynamics in condensed phase. Such as Excitation Energy Transfer dynamics in organic photovoltaic light-harvesting materials and photosynthesis via LPI-based quantum dynamical methods; Proton Transfer in enzymatic reaction sites using path-integral molecular dynamics with Jarzynski equality for calculating free energy change from nonequilibrium MD simulations.
• Ultrafast nonlinear vibrational spectroscopy: develop mixed quantum-classical methods for multidimensional IR, Raman, sum-frequency vibrational spectra of liquid solutions and liquid interfaces, via LPI, Mixed Quantum-Classical Liouville (MQCL) methods.
• Reaction pathways in nonadiabatic dynamics via the novel quantum-classical transition path sampling (QCTPS): Combination of Transition Path Sampling (TPS) and quantum dynamical methods such as LPI Ehrenfest method for nonadiabatic dynamics. Applications include solar energy harvesting and conversion in photosynthesis, and electron transfer in enzymatic bio-reactions.