Valence one-electron and shake-up ionization bands of polycyclic aromatic hydrocarbons: II: azulene, phenanthrene, pyrene, chrysene, triphenylene, and perylene

Abstract

An exhaustive investigation of the outer-valence ionization spectra of azulene, phenanthrene, pyrene, chrysene, triphenylene, and perylene is presented. The analysis is based on one-particle Green's function calculations performed upon correlated [density-functional theory/Becke three-parameter Lee-Yang-Parr (DFT/B3LYP)] geometries using the third-order outer-valence Green's function [OVGF] and algebraic-diagrammatic construction [ADC(3)] schemes, as well as basis sets of improving quality (6-31G, 6-31G(*), cc-pVDZ). The ionization bands of polycyclic aromatic hydrocarbons show a great diversity, which reflects the strong impact of the molecular architecture on orbital energies. Despite the intricacy of ionization spectra and the extent of the shake-up contamination in the pi- and sigma-band systems, the ADC(3) results enable consistent insights into available ultraviolet photoelectron measurements, up to the inner-valence region. They also indirectly support recent assignments of low-lying pi(*)<--π doublet excitations in the electronic absorption spectrum of the pyrene and perylene cations by means of time-dependent density functional theory [J. Chem. Phys. 111, 8904 (1999)]. It has been found that OVGF pole strengths smaller than 0.85 very systematically foretell a breakdown of the orbital picture of ionization at the ADC(3) level.