Ultralong Rydberg Cs$_2$ Molecules Investigated by Combined ab initio Calculations and Perturbation Theory

TL;DR

This paper presents the first ab initio study of ultralong Rydberg Cs$_2$ molecules, combining calculations and perturbation theory to analyze vibrational properties and potential curves for a range of Rydberg states.

Contribution

It introduces a novel ab initio approach to studying Rydberg molecules, providing detailed potential curves and vibrational analysis for Cs$_2$ molecules with Rydberg states from n=30 to 70.

Findings

Potential curves show characteristics consistent with previous Rb$_2$ studies.

First ab initio calculations of Rydberg Cs$_2$ molecules.

Vibrational properties are successfully analyzed using perturbation theory.

Abstract

Vibrational properties of ultralong Rydberg Cs$_2$ molecules are investigated on corresponding potential curves obtained by perturbation theory. The Rydberg Cs$_2$ molecules are associated by a Rydberg Cs($nS/nP$) atom $(n=30-70)$ and a ground state Cs($6s$) atom. The starting point for the perturbation treatment of corresponding Rydberg molecular potential curves is to generate accurate atomic Rydberg states from realistic {\it ab initio} effective core potential. The calculated results have similar characteristics with available experimental and theoretical investigations on Rydberg Rb$_2$ molecules. And this is the first time that Rydberg molecules are studied at the {\it ab initio} level.