Accurate global potential energy surface for the H + OH+ collision

Area of Science:

• Quantum Chemistry
• Molecular Spectroscopy
• Computational Fluid Dynamics

Background:

• The water cation (H2O+) is a key species in atmospheric and interstellar chemistry.
• Accurate potential energy surfaces are crucial for understanding its reactivity and spectroscopy.

Purpose of the Study:

• To compute a global three-dimensional potential energy surface (3D-PES) for the water cation.
• To validate the accuracy of the computed PES against experimental and theoretical data.

Main Methods:

• Multi-Reference Configuration Interaction (MRCI) calculations with augmented correlation-consistent polarized valence basis sets (aug-cc-pV5Z).
• Basis Set Superposition (BSSE) correction was applied.
• The PES was mapped for molecular and long-range regions, including various dissociation channels.

Main Results:

• The computed 3D-PES accurately reproduces spectroscopic constants for H2O+ and its diatomic fragments.
• Vibronic spectrum, dissociation energy, and barrier to linearity show good agreement with previous studies.
• Long-range parts of the PES effectively represent diatomic potentials.

Conclusions:

• The validated 3D-PES provides a reliable tool for studying the dynamics and properties of the water cation.
• The study enhances our understanding of the water cation's behavior in different chemical environments.