Towards relativistic ECP / DFT description of chemical bonding in E112 compounds: spin-orbit and correlation effects in E112X versus HgX (X=H, Au)

Abstract

Abstract:The relativistic effective core potential (RECP) approach combined with the spinorbit DFT electron correlation treatment was applied to the study of the bonding of eka-mercury (E112) and mercury with hydrogen and gold atoms. Highly accurate small-core shape-consistent RECPs derived from Hartree-Fock-Dirac-Breit atomic calculations with Fermi nuclear model were employed. The accuracy of the DFT correlation treatment was checked by comparing the results in the scalar-relativistic (spin-orbit-free) limit with those of high level scalar-relativistic correlation calculations within the same RECP model. E112H was predicted to be slightly more stable than its lighter homologue (HgH). The E112-Au bond energy is expected to be ca. 25-30 % weaker than that of Hg-Au. The role of correlations and magnetic (spin-dependent) interactions in E112-X and Hg-X (X=H, Au) bonding is discussed. The present computational procedure can be readily applied to much larger systems and seems to be a promising tool for simulating E112 adsorption on metal surfaces.

A comparative study of molecular hydroxides of element 113 (I) and its possible analogs: Ab initio electronic structure calculations

“…The innermost explicitly treated atomic shells (6s6p for element 113, 5s5p for thallium and astatine, 1s for oxygen) have not been correlated. Relativistic effects depending on spin which appear in the pseudopotential model as effective spin-orbit interactions have been included through the geometry-dependent corrections (∆ SO ) to the scalar relativistic energy differences; these corrections were evaluated as a difference between the results of scalar and 2c-RDFT calculations [28]. This scheme properly describes the interference of correlations and spin-dependent relativistic interactions, which is of importance for E113 compounds [29], and does not imply the smallness of such interactions.…”

Adsorption of the astatine species on a gold surface: A relativistic density functional theory study

“…This replacement is accompanied by a sharp reduction of the number of variables (i.e., the wave functions or electron densities depend only on the coordinates of the valence electrons) and by the elimination of the difficulty to approximate oscillations of the wave function in the vicinity of the atomic nuclei. RPPs were used for the representation of 60 core electrons of both, Au [19] as well as At [13]. Meanwhile, the outer-core electrons, i.e., 19 for Au and 25 for At, were explicitly described within the (7s6p6d1f) / [5s5p4d1f] Gaussian basis set for Au or the (7s12p6d1f) / [5s8p4d1f] one for At, respectively.…”

Gold–superheavy-element interaction in diatomics and cluster adducts: A combined four-component Dirac-Kohn-Sham/charge-displacement study

“…Among published studies directly related to experimental research, some use full four-component (4c) density functional theory (DFT), others combine relativistic effective core potentials (RECPs) with DFT, single reference coupled cluster theory with single, double and perturbative triple excitations (CCSD(T)), and many body perturbation theory (MBPT). Information on the adsorption behaviour of SHEs is obtained either from calculations on diatomic compounds of gold (4c/DFT, 25-28 RECP/CCSD(T), 29 RECP/DFT 29-31 ) on the assumption that these model well, at least on a relative scale, the interaction with a surface, or on complexes with gold clusters (4c/DFT, 27 37,38 with the CCSD(T) approach, thus providing a relativistic ab initio benchmark (BSS/CCSD(T)) for diatomic compounds including AuHg, AuCn, and AuFl. 39 All mentioned works mainly focus on the energetics of the gold-SHE interaction which, though of course of fundamental importance, is not the sole criterion by which a chemical interaction may be characterised and, above all, understood.…”