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.