One-Photon Absorption Properties from a Hybrid Polarizable Density Embedding/Complex Polarization Propagator Approach for Polarizable Solutions

Abstract

We present a formulation of the polarizable density embedding (PDE) method in combination with the complex polarization propagator (CPP) method for the calculation of absorption spectra of molecules in solutions. The method is particularly useful for the calculation of near-edge X-ray absorption fine structure (NEXAFS) spectra. We compare the performance of PDE-CPP with the previously formulated polarizable embedding (PE)-CPP model for the calculation of the NEXAFS spectra of adenine, formamide, glycine, and adenosine triphosphate (ATP) in water at the carbon and nitrogen K-edges, as well as of formamide and glycine at the oxygen K-edge. In general, we find only minor differences between the performance of PDE and PE for the targeted parts of the spectra, except in the case of transitions involving Rydberg states, for which nonelectrostatic effects are found to be important.

New and Efficient Equation-of-Motion Coupled-Cluster Framework for Core-Excited and Core-Ionized States

“…Fourth, these transitions appear to be much more sensitive to the effect of the environment. 30,31 Fifth, these high-lying states are metastable with respect to electron ejection, 32,33 i.e., they are Feshbach resonances that can autoionize via two-electron transitions in which one valence electron fills the core hole and a second valence electron is ejected. Thus, they are embedded in the ionization continuum and their description within Hermitian quantum mechanics is problematic.…”

A New and Efficient Equation-of-Motion Coupled-Cluster Framework for Core-Excited and Core-Ionized States

“…Fourth, these transitions appear to be much more sensitive to the effect of the environment. 30,31 Fifth, 3 core-level states become artificially stabilized (bound). By decoupling the core excitations from the rest of the configurational space, the CVS allows one to extend standard methods for excited and ionized states to the core-level states.…”

A New and Efficient Equation-of-Motion Coupled-Cluster Framework for Core-Excited and Core-Ionized States

“…Fourth, these transitions appear to be much more sensitive to the effect of the environment. 29,30 Fifth, these high-lying states are metastable with respect to electron ejection, 31,32 i.e., they are Feshbach resonances that can autoionize via two-electron transitions in which one valence electron fills the core hole and a second valence electron is ejected. Thus, they are embedded in the ionization continuum and their description within Hermitian quantum mechanics is problematic.…”