Relativistic Many-Electron SCF Correlation Diagram for Pb-Pb

Abstract

Correlation diagrams play an important role in the physical understanding and interpretation of colliding atomic systems. In the case of high-energy heavy-ion collisions they have amply shown their validity, as — for examples — in calculation of the well-known 2p_π-2p_σ rotational coupling¹, interpretation of MO x-rays², or just the empirical connection of anisotropy maxima in the MO x-rays and minima in the correlation diagram^3–4. With a discrete variational method⁵ we have developed a special program to calculate diatomic molecules in a fully relativistic regime, using numerical atomic Dirac-Fock-Slater basis functions of the two colliding atoms as well as of the Z-united atom at the center of gravity. After pre-diagonalization we are able to calculate, with a self-consistent charge procedure, correlation diagrams of very heavy systems. In Figure 1 we present the correlation diagram of Pb on Pb with 96 electrons. A careful comparison with the one-electron correlation diagram given by Kirsch et al⁶ shows a number of significant differences and physically important changes:

• (a) Even the strongest bound electronic levels are considerably screened. At R = 50fm the binding is lower by 8% for the 1(1/2)_g, 25% for the 1(1/2)_u and 40% for the 3(1/2)_g level. By R = 500fm these changes become respectively 13%, 34% and 50%.