Accurate calculations of the dissociation energy, equilibrium distance and spectroscopic constants for the Yb dimer

TL;DR

This paper presents highly precise calculations of the Yb$_2$ molecule's dissociation energy, equilibrium distance, and spectroscopic constants using advanced relativistic and correlation methods.

Contribution

It introduces a comprehensive approach combining relativistic effective core potentials and coupled cluster methods for accurate Yb$_2$ properties.

Findings

Accurate dissociation energy and equilibrium distance for Yb$_2$

Quantified relativistic and correlation effects on spectroscopic constants

Validated computational approach for closed-shell van-der-Waals systems

Abstract

The dissociation energy, equilibrium distance, and spectroscopic constants for the $^1\Sigma_g^+$ ground state of the Yb$_2$ molecule are calculated. The relativistic effects are introduced through generalized relativistic effective core potentials with very high precision. The scalar relativistic coupled cluster method particularly well suited for closed-shell van-der-Waals systems is used for the correlation treatment. Extensive generalized correlation basis sets were constructed and employed. The relatively small corrections for high-order cluster amplitudes and spin-orbit interactions are taken into account using smaller basis sets and the spin-orbit density functional theory.