Interaction Energy Surfaces for Li(2²S) and Li (2²P) With H₂

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Chemical Dynamics

Background:

• Understanding alkali metal interactions with small molecules is key to chemical reaction dynamics.
• Previous studies have explored potential energy surfaces but lacked detailed analysis of specific conformations.

Purpose of the Study:

• To calculate interaction energy surfaces for Lithium (Li) interacting with molecular Hydrogen (H2).
• To investigate the conditions leading to energy curve crossings and their implications for charge-transfer states.

Main Methods:

• Utilized approximate Hartree-Fock trial functions for calculating interaction energy surfaces.
• Analyzed energy curves for various conformations, including C2v and collinear geometries.
• Examined the wave function of attractive states involved in energy curve crossings.

Main Results:

• Observed energy curve crossings for Li(2S/2P) + H2 in C2v conformations at larger H2 internuclear distances.
• Found no energy curve crossings for collinear collisions.
• Linked the attractive state wave function to metastable negative-ion states relevant to electron-molecule scattering.
• Determined that charge-transfer states are bound only for C2v conformations of H2.

Conclusions:

• The C2v conformation is critical for the formation of bound charge-transfer states in Li-H2 interactions.
• The observed crossings provide insights into the formation of resonance charge-transfer states in alkali-molecule interactions.
• This study lays the groundwork for exploring similar phenomena in other alkali-molecule systems.