Ionization and double ionization of small water clusters

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Molecular Spectroscopy

Background:

• Understanding the electronic structure of water clusters is crucial for various chemical and physical processes.
• Ionization spectra provide insights into molecular orbital energies and electronic configurations.

Purpose of the Study:

• To calculate and analyze the valence and double ionization spectra of water molecules, dimers, and cyclic clusters ((H2O)3 and (H2O)4).
• To investigate how these spectra evolve with increasing cluster size.
• To study electronic decay mechanisms and secondary electron kinetic energy spectra in water clusters.

Main Methods:

• Ab initio Green's function methods were employed for spectral calculations.
• Detailed analysis of spectral features and their dependence on cluster size was performed.

Main Results:

• Calculated valence and double ionization spectra for water, dimer, trimer, and tetramer clusters.
• Observed systematic changes in spectral profiles with increasing cluster size.
• Addressed electronic decay pathways after inner valence ionization.

Conclusions:

• The electronic structure and ionization behavior of water clusters can be accurately modeled using ab initio Green's function methods.
• Cluster size significantly influences the ionization spectra of water aggregates.
• Electronic decay is an important process following inner valence ionization in these systems.