Ultrafast dissociation features in RIXS spectra of the water molecule

• DOI: 10.1039/c8cp01807c
• Publication Date: 2018-05-04T10:34:31Z
• Authors: Emelie Ertan; Viktoriia Savchenko; Nina Ignatova; Vinícius Vaz da Cruz; Rafael C. Couto; Sebastian Eckert; Mattis Fondell; Marcus Dantz; Brian Kennedy; Thorsten Schmitt; Annette Pietzsch; Alexander Föhlisch; Faris Gel'mukhanov; Michael Odelius; Victor Kimberg
• Keywords: Ultrafast dissociation; core-excited; RIXS; ddc:540; water; 0103 physical sciences; Institut für Chemie; Inhouse research on structure dynamics and function of matter; isotope substitution; 29.29; 01 natural sciences

In this combined theoretical and experimental study we report on an analysis of the resonant inelastic X-ray scattering (RIXS) spectra gas phase water via lowest dissociative core-excited state |1s-1O4a11. We focus spectral feature near dissociation limit electronic ground state. show that narrow atomic-like peak consists overlapping contribution from RIXS channels back to first valence excited |1b-114a11 molecule. The has signatures ultrafast (UFD) in state, as by means ab initio calculations time-dependent nuclear wave packet simulations. electronically elastic channel gives substantial resonance due strong bond length dependence magnitude orientation transition dipole moment. By studying for excitation energy scan over resonance, can understand single out molecular contributions decay valence-excited Our is complemented a discussion case isotopically substituted (HDO D2O) where dynamics significantly affected heavier fragments' mass.