PNNL

Abstract

We describe a new orbital space molecular orbital (MO) decomposition approach to analyze real-time spectra. 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 the UV/vis spectrum of f-coronene. We also compare the convergence of conventional fast Fourier transformation with the recently proposed Padé appoximants approach of Bruner et al. (A. Bruner, D. LaMaster, K. Lopata, J. Chem. Theory ComputWe 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 the first excited state absorption spectra of coronene, 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP), zinc phthalocyanine (ZnPc), and nickel TPyP, this being a first study applying a semiempirical Hamiltonian to the computation of first excited state absorption spectra.. 2016, 12, 3741–3750) for MO pair spectra. Finally, two different approaches to choose the reduced orbital space are compared. Our approach provides a simplified and efficient means to analyze real-time spectra irrespective of the nature of the excitations.