Electron excitations in superheavy quasimolecules

Finite basis set approach to the two-centre Dirac problem in Cassini coordinates

“…Besides the application of the elliptic coordinates, the structure and dynamics of heavy quasi-molecules at small inter-nuclear distances can be relatively well understood within the so-called monopole approximation (Müller-Nehler & Soff 1994, Ackad & Horbatsch 2008. Such an approximation, that employs solely the spherically symmetrical part of the two-center potential, allows one to reduce the problem to the spherically-symmetric one, with a total nuclear charge distributed homogeneously on the spherical shell with the diameter equal to the internuclear distance.…”

“…For the future one may even anticipate slow collisions between high-Z bare and one-electron ions (FAIR 2001, Stöhlker et al 2007, Gumberidze et al 2009). These quasi-molecules are known to be a versatile tool for investigating a number of fundamental problems in heavy-ion atomic physics (Betz et al 1976, Müller 1976, Soff et al 1977, Rafelski et al 1978, Kirsch et al 1978, Reinhardt et al 1979, Müller et al 1983, Soff et al 1987, Müller-Nehler & Soff 1994. In particular, analysis of molecular spectra can provide unique knowledge on the relativistic, many-body and quantum electrodynamics (QED) effects in the non-perturbative domain of high nuclear charges and super strong electromagnetic fields.…”

Contribution of higher multipole terms of Coulomb interaction to ionization in low-energy heavy-ion collisions

“…In the 1970s a formation of the charged vacuum in such collisions, provided that the total nuclear charge is larger than the critical one Z c = 173, has been predicted, and the following appropriate calculations were mostly carried out in the monopole approximation of the interaction [1]. In the 2010s interest to this problem has been renewed, and the results obtained beyond this approximation were reported [2,3,4].…”

Microfield Fluctuations and Spectral Line Shapes in Strongly Coupled Two–Component Plasmas

“…In order to obtain a finite basis the (former) continuum states are cut off at sufficiently large quantum numbers. Alternatively the continuum could be handled by forming wave packets with a width that must be adjusted appropriately [42]. In Refs.…”