Structure, spectroscopy and cold collisions of the (SrNa)$^+$ ionic system

TL;DR

This study investigates the potential energy curves, spectroscopy, and cold collision behaviors of the (SrNa)+ ionic system, providing detailed quantum calculations and analyzing scattering processes relevant for cold molecule formation.

Contribution

The paper presents comprehensive ab initio calculations of potential energy curves and scattering properties for (SrNa)+, including the effects of multiple electronic states and partial waves, advancing understanding of cold ion-atom interactions.

Findings

Elastic scattering cross sections follow Wigner law at low energies.

High-energy cross sections scale as E^{-1/3}.

At least 87 partial waves are needed for convergence at 1 K.

Abstract

We perform a study on extended adiabatic potential energy curves of nearly 38 states of 1,3$\Sigma^+$, 1,3$\Pi$ and 1,3$\Delta$ symmetries for the (SrNa)$^+$ ion, though only the ground and first two excited states are used for the study of scattering processes. Full Interaction Configuration (CI) calculations are carried out for this molecule using the pseudopotential approach. In this context, it is considered that two active electrons interact with the ionic cores and all single and double excitations were included in the CI calculations. A correction including the core-core electron interactions is also considered. Using the accurate potential energy data, the ground state scattering wave functions and cross sections are obtained for a wide range of energies. We find that, in order to get convergent results for the total scattering cross sections for energies of the order 1 K, one need to take into account at least 87 partial waves. In the low energy limit ( < 1 mK), elastic scattering cross sections exhibit Wigner law threshold law behavior while in the high energy limit the cross sections go as $E^{-1/3}$. A qualitative discussion about the possibility of forming the cold molecular ion by photoassociative spectroscopy is presented.