Are MCDF calculations 101% correct in the super-heavy elements range?

Abstract

We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfiguration Dirac-Fock method. We study the effect of going beyond the average-level approximation on the determination of the ground state of element 140, and compare with the recent work of Pekka Pyykkö on the periodic table for super heavy elements [1]. We confirm that QED corrections are of the order of 1% on ionization energies. We show that the atomic number at which the 1s shell dives into the negative energy continuum is 173, and is not affected by the approximation employed to evaluate the electron-electron interaction.

Chemistry of the superheavy elements

“…Adsorption enthalpies were determined which quantify the observed sequence in volatility of MoO 2 Cl 2 > WO 2 Cl 2 ≈ SgO 2 Cl 2 . The formation of SgO 2 Cl 2 is typical for a group-6 element and in agreement with relativistic theory calculations [7]; different, however, from the formation of UCl 6 . An exciting new development paves the way to metal-organic compounds of SHEs.…”

“…In addition, there is also the possibility that the periodicity of the PTE in itself is lost, which may happen in the eighth period in the super-actinides beyond element 120 [5]. Theoreticians have been addressing these questions for more than 40 years [4][5][6][7]. The key ingredient is the relativistic treatment of the electrons and the use of an extended atomic nucleus.…”

Is the Periodic Table all right (“PT OK”)?

“…A second example motivating this assignment of a 5g row is the calculation of Indelicato et al [8], who find an 8s 2 (8p 1/2 ) 2 5g 18 closed-shell electron configuration for the isoelectronic series to the E140 atom of Z = 143−148. Thirdly, neutral-atom calculations start to occupy the first 5g states around E125 [6,[9][10][11] or E126 [12].…”

Electric dipole moments of superheavy elements: A case study on copernicium

“…In the present paper the numerical calculations for the homologous series of group 12 of the periodic table (Zn, Cd, Hg, Cn, and Uhb) were performed with extended nuclear model (3), for which bound solutions of the Dirac-Fock equations exist up to Z = 173 [75]. The dependence of EDMs on atomic number Z along group 12 of the periodic table is presented in Fig.…”

“…(7) and (8) is valid only within the atomic number Z range, where bound solutions of the Dirac equation exist (Z 137 for pointlike nuclei, Z 173 for extended nuclei). The element E162 is close to the end of the periodic table at Z = 173, where determination of a numerical wave function, even at the Dirac-Fock level, may be problematic or impossible, and one might expect a question whether perturbation theory still works in QED for elements close to Z = 173 [75].…”