Vibrational inelastic and charge transfer processes in H(+)+H2 system: an ab initio study

Area of Science:

• * Chemical Physics
• * Quantum Dynamics
• * Computational Chemistry

Background:

• * Understanding ion-molecule reactions is crucial in various fields, including plasma physics and astrochemistry.
• * Accurate potential energy surfaces (PES) are essential for reliable theoretical predictions of collision dynamics.
• * Previous theoretical studies relied on less accurate semiempirical PES.

Purpose of the Study:

• * To compute state-resolved differential cross sections, total and integral cross sections, average vibrational energy transfer, and relative probabilities for the H(+) + H2 system.
• * To investigate both direct vibrational inelastic and charge transfer processes.
• * To validate newly obtained ab initio potential energy surfaces (PES) against experimental data.

Main Methods:

• * Utilized newly computed ab initio potential energy surfaces at the full configuration interaction/cc-pVQZ level of accuracy.
• * Employed the vibrational close-coupling infinite-order-sudden approximation for quantum dynamics.
• * Used two ab initio quasidiabatic PES to model the collision system.

Main Results:

• * Computed collision attributes for H(+) + H2 system, including state-resolved cross sections and energy transfer.
• * Achieved good agreement between theoretical predictions and experimental scattering data at E(c.m.)=20 eV.
• * Demonstrated the reliability of the ab initio PES by comparing with previous theoretical studies.

Conclusions:

• * The newly developed ab initio PES accurately describe the H(+) + H2 collision dynamics.
• * The theoretical approach successfully reproduces key experimental scattering features.
• * This work provides a reliable computational framework for studying ion-molecule interactions.