SAC-CI Calculation of a Series of the Lowest 2-Pi-States of HCl+ and HBr+ Ions

TL;DR

This paper employs the SAC-CI method to calculate the electronic structure and potential energy curves of low-lying 2Pi-states of HCl+ and HBr+ ions, revealing their asymptotic behavior and complex interactions.

Contribution

It presents ab initio calculations of multiple 2Pi-states of HCl+ and HBr+ ions using the SAC-CI method, providing detailed potential energy curves and insights into their electronic behavior.

Findings

Potential energy curves show asymptotic behavior starting at ~8 a0.

States are well separated at larger distances.

Complex interactions occur among 4^2Pi-6^2Pi states at short distances.

Abstract

The symmetry-adapted-cluster configuration interaction (SAC-CI) method is used for ab initio calculation of electronic structure of HCl+ and HBr+ molecular ions. Potential energy curves (PEC) are obtained for a series of low-lying 2Pi-states starting from the ground state, X-2Pi. The PEC for both HCl+ and HBr+ reveal the corresponding asymptotic behavior beginning from the interatomic distances ~8 a0 for the first three states. These states are well separated, while a complex behavior occurs for the set of 4^2Pi-6^2Pi states with a bound character at short distances.