Spatial Decay and Limits of Quantum Solute-Solvent Interactions

Molecular excitations in the liquid-phase environment are renormalized by the surrounding solvent molecules. Herein, we employ the GW approximation to investigate the solvation effects on the ionization energy of phenol in various solvent environments. The electronic effects differ by up to 0.4 eV among the five investigated solvents. This difference depends on both the macroscopic solvent polarizability and the spatial decay of the solvation effects. The latter is probed by separating the electronic subspace and the GW correlation self-energy into fragments. The fragment correlation energy decays with increasing intermolecular distance and vanishes at similar to 9 angstrom, and this pattern is independent of the type of solvent environment. The 9 angstrom cutoff defines an effective interacting volume within which the ionization energy shift per solvent molecule is proportional to the macroscopic solvent polarizability. Finally, we propose a simple model for computing the ionization energies of molecules in an arbitrary solvent environment.

Automated summary

In this study, the GW approximation is used to investigate the solvation effects on the ionization energy of phenol in different solvent environments. The electronic effects vary by up to 0.4 eV among the five solvents examined, depending on the macroscopic solvent polarizability and the spatial decay of the solvation effects. By separating the electronic subspace and the GW correlation self-energy into fragments, it is observed that the fragment correlation energy decays with increasing intermolecular distance and vanishes at approximately 9 angstrom, independent of the solvent environment type. A simple model for computing the ionization energies of molecules in any solvent environment is proposed.