Author Archives: Li Group

Paper on exciton dynamics in silver nanowires published online

A recently published paper,”Real-Time TDDFT Studies of Exciton Decay and Transfer in Silver Nanowire Arrays,” focuses on exciton dynamics, transfer, and decay in silver nanowires. One silver nanowire was initially excited and then coupled to a second nanowire with varying separation distances between them. The electronic density of the total system was then propagated in time with real-time TDDFT. Exciton transfer and diffusion can then be interpreted by observing the oscillating dipole of the total system. This paper focuses on the dephasing mechanism and presents an upper bound for exciton decay time. This work is published in the Journal of Physical Chemistry C.

Feizhi and David’s paper on non-equilibrium TD-PCM is now online.

The group’s first publication of 2015 details work in an area we have been interested in for some time: including environmental response in our simulations. The Polarizable Continuum Model (PCM) is often used to account for the dielectric response of the media surrounding the molecule of interest. Previous attempts at time-dependent PCM only accounted for the environment being in equilibrium with, for example, the photoexcited solute at each time step of the simulation. This new formalism, derived and implemented by Feizhi, accounts for non-equilibrium environmental response as the surrounding electronic structure evolves following an excitation of the solute. The article is titled “Time-Dependent Non-equilibrium Dielectric Response in QM/Continuum Approaches” and is published in The Journal of Chemical Physics.

Why settle for one Italian postdoc when you can have two?

The group is happy to welcome Franco Egidi. Franco recently finished his Ph.D. with Vincenzo Barone and Chiara Cappelli at Scuola Normale Superiore in Pisa. He has published a number of papers on environmental effects, optical rotation, and vibrational spectroscopy. Franco is a welcome addition to the group and will be a big help on a number of new projects starting up.

Erica passed her General Exam!

Congratulations to Erica on passing her General Exam. Erica presented her work on using a Discrete Variable Representation (DVR) to describe ion mobility in quantum dot nanostructures. Congrats to Erica!

Two recent publications are now available online

Josh Goings and Feizhi Ding published a paper in the Journal of Chemical Physics titled “Ab Initio Non-Relativistic Spin Dynamics“. The Generalized Hartree-Fock density was coupled to a magnetic field and propagated in real time. This was a non-relativist two-component spinor method, called TDN2C. This method allows for the resolution of non-collinear electron spins precessing about the magnetic field, the well-known Larmor precession. When additional coupling mechanisms are introduced this scheme will be able to resolve complex time-dependent magnetic properties. Josh also published a paper with our collaborators in the Gamelin group in the Journal of Physical Chemistry C titled “Theoretical Characterization of Conduction-Band Electrons in Photodoped and Aluminum-Doped Zinc Oxide (AZO) Quantum Dots“. This paper investigated the electronic structure of Al-doped ZnO nanocrystals. Many of the spectroscopic features in these structures can be interpreted in the so-called “super” orbitals. These orbitals are similar to those seen in a hydrogenic systems or a quantum mechanical particle in a spherical potential.

The group welcomes Sajan Silwal

We are pleased to welcome a new graduate student, Sajan Silwal to the group. Sajan originally hails from Nepal and obtained his undergraduate degree at Kalamazoo College in Michigan. There he did some experimental work looking on photodissociation, but became interested in programming and decided to switch to theory for graduate school. Welcome Sajan!

It’s a big week for fellowships!

The group got some great news this week as David Lingerfelt, Josh Goings, and Patrick Lestrange all received the UW Graduate Student Merit Fellowship. This fellowship is awarded in recognition of outstanding academic scholarship based upon accomplishments in research and graded course work. This week, Patrick and David also received a fellowship through UW’s Clean Energy Institute. This fellowship is awarded to UW students working on projects related to solar energy capture and storage. Patrick will be working on modeling X-ray absorption spectroscopy in order to better characterize photovoltaic materials. David will be working on Li-ion storage in quantum dot nanostructures. Congratulations to everyone!

Congratulations to Xiaosong on his 100th publication!

Xiaosong’s 100th publication has just been accepted to The Journal of Chemical Physics. Starting in 1999, Xiaosong has published papers focused on a variety of topics such as wave function and geometry optimization, electronic and nuclear dynamics, and various types of spectroscopies. This most recent paper is especially exciting because it focuses on spin dynamics, a powerful new direction for the group. One hundred publications is a great accomplishment and we’re looking forward to a few hundred more. Congrats to Xiaosong!