Approximate Description of Excited State PES

In order to compute vibrationally resolved electronic spectra different models are now available, which differ in their conceptual approach to the transition, vertical or adiabatic, as well as the level of approximation of the respective PESs of the initial and final states [270]. Within vertical models (such as the vertical 

Additionally, various approximations on the transition dipole moment, namely Franck-Condon (FC), Herzberg-Teller (HT), or Franck-Condon Herzberg-Teller (FCHT) can be appfied. From the computational perspective, the state-of-the-art methods rooted into TD-DFT are nowadays the most effective routes to treat medium-to-large molecular systems. Since analytical second 

In this section, some representative case studies are discussed with the aim of illustrating the capabilities of the theoretical models sketched in the preceding sections for a reliable description of the structure, spectroscopy, and thermodynamics of small-to-larger organometalic systems, isolated in the gas phase and embedded in more complex environments. 

Thermodynamics and Vibrational Spectroscopy Beyond Harmonic Approximation  

1 Accurate Results for Isolated Glycine from Hybrid CC/DFT Computations 

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Figure 10.7 Schematic representation of adiabatic and vertical models for the approximate description of excited-state PES. Differences between the "true" PES (dashed lines) and harmonic PES, for both models, are highlighted.

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