title: O 1s --> sigma* resonance in O2: inadequacy of only two exchange-split components.
abstract: The O 1s-->sigma* transition below the O K-edge in O2 has been investigated by absorption, constant ionic state (CIS) experiments, and extensive configuration interaction calculations. CIS scans of the three lowest-lying final states reached in resonant Auger decay provide a wealth of information on energy range, symmetry, and spin multiplicity of the intermediate states with sigma* character. We conclude that the identification of only two exchange-split components is inadequate because a complex manifold of states with sigma* character exists with no unique energy difference between related states.
authors.affiliation: Department of Chemical Sciences and Technologies and INFM, University Tor Vergata, 00133 Rome, Italy.
authors.forename: M N
authors.initials: MN
authors.lastname: Piancastelli
authors.forename: A
authors.initials: A
authors.lastname: Kivimäki
authors.forename: V
authors.initials: V
authors.lastname: Carravetta
authors.forename: I
authors.initials: I
authors.lastname: Cacelli
authors.forename: R
authors.initials: R
authors.lastname: Cimiraglia
authors.forename: C
authors.initials: C
authors.lastname: Angeli
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Coreno
authors.forename: M
authors.initials: M
authors.lastname: de Simone
authors.forename: G
authors.initials: G
authors.lastname: Turri
authors.forename: K C
authors.initials: KC
authors.lastname: Prince