One-Electron Energy Spectra of Heavy Highly Charged Quasimolecules: Finite-Basis-Set Approach

Artem A Kotov,Vladimir M Shabaev,Dmitry A Glazov,Günter Plunien

doi:10.3390/atoms9030044

Abstract

The generalized dual-kinetic-balance approach for axially symmetric systems is employed to solve the two-center Dirac problem. The spectra of one-electron homonuclear quasimolecules are calculated and compared with the previous calculations. The analysis of the monopole approximation with two different choices of the origin is performed. Special attention is paid to the lead and xenon dimers, Pb82+–Pb82+–e− and Xe54+–Xe54+–e−, where the energies of the ground and several excited σ-states are presented in the wide range of internuclear distances. The developed method provides the quasicomplete finite basis set and allows for the construction of perturbation theory, including within the bound-state QED.

Highlights

Due to the critical phenomena of the bound-state quantum electrodynamics, such as spontaneous electron–positron pair production, quasimolecular systems emerging in ion–ion or ion–atom collisions have attracted much interest [1,2,3,4,5,6,7,8,9]
While collisions of highly charged ions with neutral atoms are presently available for experimental investigations, in particular at the GSI Helmholtz Center for Heavy Ion Research [10,11,12], the upcoming experiments at the GSI/FAIR [13], NICA [14], and HIAF [15] facilities might even allow the observation of the heavy ion–ion collisions
We investigate the difference between the two-center values and those obtained within the monopole approximation

Summary

Introduction

Due to the critical phenomena of the bound-state quantum electrodynamics, such as spontaneous electron–positron pair production, quasimolecular systems emerging in ion–ion or ion–atom collisions have attracted much interest [1,2,3,4,5,6,7,8,9]. Within the Born–Oppenheimer approximation, the one-electron problem is reduced to the Dirac equation with the Coulomb potential of two nuclei at a fixed internuclear distance D. This problem was investigated previously by a number of authors; see, e.g., [16,21,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38]. We consider the method based on the dual-kinetic-balanced finitebasis-set expansion [39] of the electron wave function for axially symmetric systems [40]

Methods

Results

Conclusion