Vibrational fine structure in the N 1s→π∗ resonance of the N2 molecule physisorbed on the Cu(100) surface

High-resolution photoabsorption spectra at the N 1s→π∗ resonance of N2 physisorbed on the Cu(100) surface are reported. The vibrational fine structure of this resonance could be resolved, allowing the determination of the vibrational constants, the lifetime and intramolecular distances of the core-excited states of the physisorbed molecules. The obtained fundamental vibrational constants are compared with the corresponding vibrational parameters for the gas phase.