On the controversial assignment of the photoelectron spectrum of SO₃

Abstract

The ionization potentials of SO₃ are calculated by a many-body Green's function method which includes the effects of electronic reorganization and correlation. A definitive assignment of the photoelectron spectrum of SO₃ is given. The ordering of the ionization potentials is (with increasing energy): 1a ₂′, 1e″(π), 3e′, 2e′ + 1a ₂″(π), 2a ₁′. Two ionization processes give rise to the fourth band. A tentative value for the vertical electron affinity of SO₃ is given : 0·8 eV.