Line shapes of1s→π*excited molecular clusters

Abstract

The line shapes of $1s\ensuremath{\rightarrow}{\ensuremath{\pi}}^{*}$-excited molecular Van der Waals clusters are compared to those of the corresponding isolated molecules. Small, but distinct spectral changes are observed, such as spectral shifts, line broadening, and changes in intensity. These are assigned in terms of variations in motion of the core-excited molecule within the molecular clusters using a simple model. Contributions from intra- and inter-molecular vibrations in core-excited clusters, which contribute to the experimentally observed spectral changes, are discussed.