High resolution photoabsorption and photofragment fluorescence spectroscopy of water between 10.9 and 12 eV.

This work presents absorption and photofragment fluorescence spectra of water (H[sub 2]O and D[sub 2]O) simultaneously recorded at rotational resolution and at room temperature, by means of a synchrotron radiation source in the range 10.9–12 eV, covering the nd intense series from n=3 to 8. The Rydberg states observed are assigned in the light of the most advanced theoretical work available [M. S. Child, Philos. Trans. R. Soc. London, Ser. A 355, 1623 (1997)], and by reference to the stretching and bending mode progressions. Comparison between absorption and fluorescence spectra is shown to reveal a fast predissociation mechanism involving the linear 3pb[sub 2] [sup 1]B[sub 2] state, and permits the identification of its (0,14,0) vibrational level observed in the absorption spectra. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]