Chapter 7: Towards the accurate simulation of UV/Vis spectra in solution: combining the EOM-CCSD method with polarizable solvation models within state-specific and linear-response formalisms

In this report, we review the theory and present some novel applications for the combination of highly accurate quantum mechanical methods belonging to the coupled cluster (CC) family and semiclassical solvation models. The goal is to simulate electronic transitions of solvated chromophores with an accuracy and computational effort that is comparable to those for isolated molecules. Two formalisms for this coupling are described: state-specific (SS) and linear-response (LR), and their strengths and weaknesses are discussed in the context of CC methods and the polarizable continuum model of solvation (PCM). Numerical results are shown for a selection of medium size chromophores in polar solvents where calculated transition energies at CC and density functional theory (DFT) levels are compared to experimental data. These results show the potential of multiscale models that combine high-level CC theory with lower, more computationally efficient levels of theory for studying the photochemistry of chromophores in condensed phase.