University of Southern California
B.S. in Mathematics and Chemistry, 2007
- Higher-energy solutions to the Kohn-Sham equations and their spin-restricted variants The Hohenberg-Kohn theorem only applies to ground states, yet higher-energy solutions to the Kohn-Sham equations can be surprisingly good approximations for excited states. These ΔSCF calculations are also relatively fast, enabling excited-state calculations at the computational cost of ground-state calculations. Why are ΔSCF excitation energies often as good as those from linear response TDDFT? Is a spin-restricted variant such as ROKS better than post facto spin purification?
- Construction of free energy surfaces for electron transfer reactions in condensed phases: By coupling a constrained DFT approach to diabatization of electronic states with a polarizable QM/MM molecular dynamics procedure for sampling configuration space, we can parametrize free energy surfaces for electron transfer reactions.
- Fluorescence quenching by photoinduced electron transfer in a Zn2+ chemical sensor A common motif for visual detection of a particular chemical (the analyte) in a sample is to employ a fluorescent chemical sensor whose fluorescence intensity is altered by binding to the analyte. In many cases, this behavior is governed by a photoinduced electron transfer fluorescence quenching mechanism. We are using time-dependent DFT and constrained DFT to study the plausibility of this mechanism in a Zn2+ sensor.