Investigating the Ground-State and Ionization Processes of Hydrogen Peroxide Dimers Using Sequentially Combined...

Area of Science:

• Computational chemistry
• Molecular physics
• Quantum chemistry

Background:

• Hydrogen peroxide (H2O2) dimers are complex molecular systems.
• Understanding their structures and ionization energies is crucial for chemical physics.
• Recent advancements in beam experiments have enabled isolation of H2O2 clusters.

Purpose of the Study:

• To investigate the structures and ionization energies (IEs) of various hydrogen peroxide dimer conformations.
• To provide accurate theoretical data for comparison with experimental findings.
• To guide future research on molecular clusters and their ionization processes.

Main Methods:

• Utilized coupled-cluster with single, double, and perturbative triple excitations (CCSD(T)) for ground-state properties.
• Employed equation-of-motion ionization potential coupled-cluster with single and double excitations (EOMIP-CCSD) for IEs.
• Applied correlation-consistent basis sets and extrapolation to the complete basis set limit, including core-correlation effects.

Main Results:

• Identified stable conformations of H2O2 dimers, all within 10 kJ/mol of the most stable structure.
• Calculated the first ionization energy for conformation I as 11.72 eV and for conformation V as 11.58 eV.
• Observed differences in IEs across conformations, potentially aiding experimental data assignment.

Conclusions:

• The computed ionization energies offer valuable insights into H2O2 dimer behavior.
• The theoretical framework provides a foundation for interpreting experimental results.
• This study serves as a guide for researchers studying molecular clusters and ionization phenomena.