
Size dependent errors in densityfunctional theory Our recent studies into the errors in the excitation energies and ionization potentials as computed with densityfunctional theory (DFT) show sizedependent trends. This can be related to the delocalization error of standard density functionals; we are investigating how the inclusion of exact exchange into the functional affects these sizedependent errors 
Determining accurate solvation models 


Modeling the absorption spectra of coupled chromophores We want to move beyond understanding chromophore optical properties at the single molecule level and also understand them when they are coupled together in a thin film material. Absorption spectra are often quite different in dilute solution than in the aggregate, and our research aims to relate the configuration of multiple chromophores to the shifting and broadening of the computed and measured absorption spectra. 

Realtime electron dynamics with timedependent densityfunctional theory Electronic charge transfer is key to harnessing photon derived energy. After photoexcitation, the excited electrons must be transferred between phases, materials, or molecules. Thus, developing and benchmarking a method to directly model these electron dynamics is key to understanding these charge transfer processes at a fundamental level. Realtime TDDFT is a promising technique wherein the electron density matrix is explicitly propagated in time. This technique goes beyond the standard perturbative linear response TDDFT method, allowing the electron dynamics to respond to large perturbations such as an applied laser field. We use, develop, and validate this coherent superposition singledeterminant density propagation method, examining the validity of the adiabatic approximation in the realm of strongfield perturbation of the electron density. 