A Semiempirical Effective Hamiltonian Based Approach for Analyzing Excited State Wave Functions and Computing Excited State Absorption Spectra Using Real-Time Dynamics

Ghosh, S.; Asher, J. C.; Gagliardi, L.; Cramer, C. J.; Govind, N.
J. Chem. Phys. 2019, 150, 104103 (doi:10.1063/1.5061746).

We describe a new approach to extract information about an excited state wave function using a reduced orbital space molecular orbital (MO) decomposition approach for time-dependent density obtained from real-time dynamics. We also show how this information about the excited state wave function can be used to accelerate the convergence of real-time spectra and model excited state electron dynamics. We have combined this approach with our recent implementation of the real-time INDO/S method to study the solvatochromic shift of Nile Red in acetone, ethanol, toluene and n-hexane solvents and, for the first time, the excited state absorption (ESA) spectra of coronene, 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP), zinc phthalocyanine (ZnPc), and nickel TPyP using a semiempirical Hamiltonian.