Theoretical study of electronic structure and ionization spectrum of γ-pyrone

Abstract

The electronic structure and ionization spectrum of γ-pyrone (4 H -pyran-4-one) were studied using the third-order algebraic-diagrammatic construction method for a one-particle Green’s function [IP-ADC(3)] and a number of other high-level quantum chemical methods. The results of the calculations are used to interpret the recently obtained photoelectron spectra. A number of new assignments are proposed concerning the nature of the photoelectron maxima of γ-pyrone above 12 eV, where, according to our calculations, there is a significant violation of the single-electron ionization picture due to electron correlation effects. The results obtained significantly change the interpretation of the spectrum available in the literature.