Investigating properties of Cl$^-$ and Au$^-$ ions using relativistic many-body methods

TL;DR

This study uses advanced relativistic many-body methods to accurately compute the properties of Cl$^-$ and Au$^-$ ions, including their polarizabilities and ionization potentials, with results validated against experimental data.

Contribution

It introduces a comprehensive relativistic many-body computational approach for negative ions, combining Dirac-Fock, perturbation, and coupled-cluster methods for detailed property analysis.

Findings

Calculated electric dipole polarizabilities and ionization potentials for Cl$^-$ and Au$^-$.

Results show good agreement with experimental and previous theoretical data.

Demonstrated the effectiveness of relativistic many-body methods for negative ion properties.

Abstract

We investigate ground state properties of singly charged chlorine (Cl$^-$) and gold (Au$^-$) negative ions by employing four-component relativistic many-body methods. In our approach, we attach an electron to the respective outer orbitals of chlorine (Cl) and gold (Au) atoms to determine the Dirac-Fock (DF) wave functions of the ground state configurations of Cl$^-$ and Au$^-$, respectively. As a result, all the single-particle orbitals see the correlation effects due to the appended electron of the negative ion. After obtaining the DF wave functions, lower-order many-body perturbation methods, random-phase approximation, and coupled-cluster (CC) theory in the singles and doubles approximation are applied to obtain the ground state wave functions of both Cl$^-$ and Au$^-$ ions. Then, we adopt two different approaches to the CC theory -- a perturbative approach due to the dipole operator to determine electric dipole polarizability and an electron detachment approach in the Fock-space framework to estimate ionization potential. Our calculations are compared with the available experimental and other theoretical results.