title: Dynamic stabilization in 1sigma(u)-->1pi(g) excited nitrogen clusters.
abstract: High-resolution 1s near-edge spectra of molecular nitrogen and variable size nitrogen clusters obtained using monochromatic synchrotron radiation from the high brilliance BESSY-II storage ring facility are reported. The vibrationally resolved 1sigma(u)-->1pi(g) core-to-valence excitation band of clusters shows a distinct redshift of 6+/-1 meV relative to the isolated molecule, but the vibrational structure and linewidths are essentially unchanged. This shift is assigned to dynamic stabilization of 1sigma(u)-->1pi(g) excited molecules in clusters, arising from the dynamic dipole moment generated by core-hole localization in the low-symmetry cluster field. This leads to changes in intermolecular interactions compared to the ground-state cluster. Such spectral shifts are expected to occur generally in molecular clusters and in the corresponding condensed phase.
authors.affiliation: Fachbereich Physik, Universität, Osnabrück, Barbarastrasse 7, 49069 Osnabrück, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Flesch
authors.forename: A A
authors.initials: AA
authors.lastname: Pavlychev
authors.forename: J J
authors.initials: JJ
authors.lastname: Neville
authors.forename: J
authors.initials: J
authors.lastname: Blumberg
authors.forename: M
authors.initials: M
authors.lastname: Kuhlmann
authors.forename: W
authors.initials: W
authors.lastname: Tappe
authors.forename: F
authors.initials: F
authors.lastname: Senf
authors.forename: O
authors.initials: O
authors.lastname: Schwarzkopf
authors.forename: A P
authors.initials: AP
authors.lastname: Hitchcock
authors.forename: E
authors.initials: E
authors.lastname: Rühl