32 research outputs found
Generating and grading 34 Optimised Norm-Conserving Vanderbilt Pseudopotentials for Actinides and Super Heavy Elements in the PseudoDojo
In the last decades, material discovery has been a very active research field
driven by the necessity of new materials for different applications. This has
also included materials incorporating heavy elements, beyond the stable
isotopes of lead. Most of actinides exhibit unique properties that make them
useful in various applications. Further, new heavy elements, taking the name of
super-heavy elements, have been synthesized, filling previously empty space of
Mendeleev periodic table. Their chemical bonding behaviour, of academic
interest at present, would also benefit of state-of-the-art modelling
approaches. In particular, in order to perform first-principles calculations
with planewave basis sets, one needs corresponding pseudopotentials. In this
work, we present a series of fully-relativistic optimised norm-conserving
Vanderbilt pseudopotentials (ONCVPs) for thirty-four actinides and super-heavy
elements. The scalar relativistic version of these ONCVPs is tested by
comparing equations of states for crystals, obtained with \textsc{abinit} 9.6,
with those obtained by all-electron zeroth-order regular approximation (ZORA)
calculations performed with the Amsterdam Modelling Suite BAND code.
-Gauge and -Gauge indicators are used to validate these
pseudopotentials. This work is a contribution to the PseudoDojo project, in
which pseudopotentials for the whole periodic table are developed and
systematically tested. The fully-relativistic pseudopotential files (i.e.
including spin-orbit coupling) are available on the PseudoDojo web-interface
pseudo-dojo.org under the name NC FR (ONCVPSP) v4.x. Pseudopotentials are made
available in psp8 and UPF2 formats, both convenient for \textsc{abinit}, the
latter being also suitable for Quantum ESPRESSO
Online chemical adsorption studies of Hg, Tl, and Pb on SiO2 and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA
Online gas-solid adsorption studies with single-atom quantities of Hg, Tl, and Pb, the lighter homologs of the superheavy elements (SHE) copernicium (Cn, Z =112), nihonium (Nh, Z =113), and flerovium (Fl, Z =114), were carried out using short-lived radioisotopes. The interaction with Au and SiO 2 surfaces was studied and the overall chemical yield was determined. Suitable radioisotopes were produced in fusion-evaporation reactions, isolated in the gas-filled recoil separator TASCA, and flushed rapidly to an adjacent setup of two gas chromatography detector arrays covered with SiO 2 (first array) and Au (second array). While Tl and Pb adsorbed on the SiO 2 surface, Hg interacts only weakly and reached the Au-covered array. Our results contribute to elucidating the influence of relativistic effects on chemical properties of the heaviest elements by providing experimental data on these lighter homologs
Relativistic electronic structure studies on the heaviest elements
AbstractSpectacular developments in relativistic quantum theory and computational algorithms in the last two decades allowed for accurate predictions of properties of the heaviest elements and their experimental behaviour. The most recent works in this area of investigations are overviewed. Preference is given to those related to experimental research. The role of relativistic effects is elucidated.</jats:p
Relativistic effects on the electronic structure of the heaviest elements. Is the Periodic Table endless?
Great progress has been achieved in the last few decades in the synthesis of superheavy elements (SHEs) and experimental studies of their physio-chemical properties. At the same time, remarkable developments in the relativistic electronic structure theory allowed for accurate predictions of properties of SHEs and their compounds. Those theoretical investigations, often carried out in a close link to the experimental research, have largely contributed to better understanding of the chemistry of these elements and the role of relativistic effects. In this short review, recent achievements in the research activities on SHEs are overviewed