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The chemistry of superheavy elements (Z = 104) is actively investigated in atom-at-a-time experiments of volatility through adsorption on gold surfaces. In this context, common guidelines for interpretation based on group trends in the periodic table should be used cautiously, because relativistic effects play a central role and may cause predictions to fall short. In this paper, we present an all-electron four-component Dirac-Kohn-Sham comparative study of the interaction of gold with Cn (Z = 112), Fl (Z = 114), and Uuo (Z = 118) versus their lighter homologues of the 6th period, Hg, Pb, and Rn plus the noble gas Xe. Calculations were carried out for Au-E (E = Hg, Cn, Pb, Fl, Xe, Rn, Uuo), Au7- and Au20-E (E = Hg, Cn, Pb, Fl, Rn) complexes, where Au7 (planar) and Au20 (pyramidal) are experimentally determined clusters having structures of increasing complexity. Results are analysed both in terms of the energetics of the complexes and of the electron charge rearrangement accompanying their formation. In line with the available experimental data, Cn and more markedly Fl are found to be less reactive than their lighter homologues. On the contrary, Uuo is found to be more reactive than Rn and Xe. Cn forms the weakest bond with the gold atom, compared to Fl and Uuo. The reactivity of Fl decreases with increasing gold-fragment size more rapidly than that of Cn and, as a consequence, the order of the reactivity of these two elements is inverted upon reaching the Au20-cluster adduct. Density difference maps between adducts and fragments reveal similarities in the behaviour of Cn and Xe, and in that of Uuo and the more reactive species Hg and Pb. These findings are given a quantitative ground via charge-displacement analysis. [ABSTRACT FROM AUTHOR]

Static dipole polarizabilities of element 119 and its singly charged cation are calculated, along with those of its lighter homologs, Cs and Fr. Relativity is treated within the 4-component Dirac-Coulomb formalism and electron correlation is included by the single reference coupled cluster approach with single, double, and perturbative triple excitations (CCSD(T)). Very good agreement with available experimental values is obtained for Cs, lending credence to the predictions for Fr and element 119. The atomic properties in group-1 are largely determined by the valence ns orbital, which experiences relativistic stabilization and contraction in the heavier elements. As a result, element 119 is predicted to have a relatively low polarizability (169.7 a.u.), comparable to that of Na. The adsorption enthalpy of element 119 on Teflon, which is important for possible future experimental studies of this element, is estimated as 17.6 kJ/mol, the lowest among the atoms considered here. [ABSTRACT FROM AUTHOR]

Energy-consistent two-component semi-local pseudopotentials for the superheavy elements with atomic numbers 111-118 have been adjusted to fully relativistic multi-configuration Dirac-Hartree-Fock calculations based on the Dirac-Coulomb Hamiltonian, including perturbative corrections for the frequency-dependent Breit interaction in the Coulomb gauge and lowest-order quantum electrodynamic effects. The pseudopotential core includes 92 electrons corresponding to the configuration [Xe]4f 145d105f 14. The parameters for the elements 111-118 were fitted by two-component multi-configuration Hartree-Fock calculations in the intermediate coupling scheme to the total energies of 267 up to 797 J levels arising from 31 up to 62 nonrelativistic configurations, including also anionic and highly ionized states, with mean absolute errors clearly below 0.02 eV for averages corresponding to nonrelativistic configurations. Primitive basis sets for one- and two-component pseudopotential calculations have been optimized for the ground and excited states and exhibit finite basis set errors with respect to the finite-difference Hartree-Fock limit below 0.01 and 0.02 eV, respectively. General contraction schemes have been applied to obtain valence basis sets of polarized valence double- to quadruple-zeta quality. Results of atomic test calculations in the intermediate coupling scheme at the Fock-space coupled-cluster level are in good agreement with those of corresponding fully relativistic all-electron calculations based on the Dirac-Coulomb-Breit Hamiltonian. The results demonstrate besides the well-known need of a relativistic treatment at the Dirac-Coulomb level also the necessity to include higher-order corrections for the superheavy elements. [ABSTRACT FROM AUTHOR]

Fully relativistic (four-component) density-functional theory calculations were performed for elements 112 and 114 and their lighter homologs, Hg and Pb, interacting with gold systems, from an atom to a Aun cluster simulating the Au(111) surface. Convergence of the adatom-metal cluster binding energies Eb with cluster size was reached for n>90. Hg, Pb, and element 114 were found to preferably adsorb at the bridge position, while element 112 was found to preferably adsorb at a hollow site. Independently of the cluster size, the trend in Eb is Pb>114>Hg>112. The obtained Eb for Pb and element 112 are in good agreement with the measured adsorption enthalpies of these elements on gold, while the Hg value is obviously underestimated, confirming the observation that adsorption takes place not on the surface but in it. A comparison of chemical bonding in various systems shows that element 114 should be more reactive than element 112: A relative inertness of the latter is caused by the strong relativistic stabilization of the 7s atomic orbital. On the contrary, van der Waals bonding in element 114 systems should be weaker than in those of element 112 due to its larger radius. [ABSTRACT FROM AUTHOR]

The interaction of the inert gases Rn and element 118 with various surfaces has been studied on the basis of fully relativistic ab initio Dirac–Coulomb CCSD(T) calculations of atomic properties. The calculated polarizability of element 118, 46.3 a.u., is the largest in group 18, the ionization potential is the lowest at 8.91 eV, and the estimated atomic radius is the largest, 4.55 a.u. These extreme values reflect, in addition to the general trends in the Periodic Table, the relativistic expansion and destabilization of the outer valence 7p3/2 orbital. Van der Waals coefficients C3 and adsorption enthalpies ΔHads of Ne through element 118 on noble metals and inert surfaces, such as quartz, ice, Teflon, and graphite, were calculated in a physisorption model using the atomic properties obtained. The C3 coefficients were shown to steadily increase in group 18, while the increase in ΔHads from Ne to Rn does not continue to element 118: The large atomic radius of the latter element is responsible for a decrease in the interaction energy. We therefore predict that experimental distinction between Rn and 118 by adsorption on these types of surfaces will not be feasible. A possible candidate for separating the two elements is charcoal; further study is needed to test this possibility. [ABSTRACT FROM AUTHOR]

Multiconfiguration Dirac-Fock method is employed to calculate the excitation energies, ionization potentials, oscillator strengths, and radii for all neutral and up to four times ionized species of element Uuq, as well as the homolog elements Ge, Sn, and Pb. Using an extrapolative scheme, improved ionization potentials of Uuq were obtained with an uncertainty of less than 2000 cm-1. Two relatively stronger resonance transitions are predicted for the element Uuq. In particular, the strongest line in Uuq, corresponding to the [6d107s27p3/28s1/2]1→[6d107s27p3/22]2 transition at 22 343 cm-1, just lies in the prime energy region of experimental measurement. [ABSTRACT FROM AUTHOR]

The interaction of elements 112 and 114 with inert surfaces has been studied on the basis of fully relativistic ab initio Dirac-Coulomb CCSD(T) calculations of their atomic properties. The calculated polarizabilities of elements 112 and 114 are significantly lower than corresponding Hg and Pb values due to the relativistic contraction of the valence ns and np1/2 orbitals, respectively, in the heavier elements. Due to the same reason, the estimated van der Waals radius of element 114 is smaller than that of Pb. The enthalpies of adsorption of Hg, Pb, and elements 112 and 114 on inert surfaces such as quartz, ice, and Teflon were predicted on the basis of these atomic calculations using a physisorption model. At the present level of accuracy, -ΔHads of element 112 on these surfaces is slightly (about 2 kJ/mol) larger than -ΔHads(Hg). The calculated -ΔHads of element 114 on quartz is about 7 kJ/mol and on Teflon is about 3 kJ/mol smaller than the respective values of -ΔHads(Pb). The trend of increasing -ΔHads in group 14 from C to Sn is thus reversed, giving decreasing values from Sn to Pb to element 114 due to the relativistic stabilization and contraction of the np1/2 atomic orbitals. This is similar to trends shown by other atomic properties of these elements. The small difference in ΔHads of Pb and element 114 on inert surfaces obtained within a picture of physisorption contrasts with the large difference (more than 100 kJ/mol) in the chemical reactivity between these elements. [ABSTRACT FROM AUTHOR]

Presents one- and two-component relativistic and nonrelativistic energy adjusted pseudopotentials and basis sets for the elements 111 and 112. Calculations on the positively charged monohydride of the superheavy element 112; Electron correlation; Couple cluster level and fine structure effects derived.

Relativistic energy-consistent pseudopotentials for the superheavy elements with nuclear charges 119 and 120 replacing 92 electrons of a [Xe]4f 145d105f 14 core were adjusted to relativistic multi-configuration Dirac-Coulomb-Breit finite nucleus all-electron reference data including lowest-order quantum electrodynamic effects, i.e., vacuum polarization and electron self-energy. The parameters were fitted by two-component multi-configuration Hartree-Fock calculations in the intermediate coupling scheme to the total valence energies of 131 to 140 relativistic states arising from 31 to 33 nonrelativistic configurations covering also anionic and highly ionized states, with mean absolute errors for the nonrelativistic configurations below 0.01 eV. Primitive basis sets for one- and two-component calculations with errors below 0.02 and 0.03 eV to the Hartree-Fock limit, respectively, as well as general contractions of these basis sets with double- to quadruple-zeta quality were obtained. Atomic highly correlated test calculations using the Fock-space coupled-cluster method yield for valence excitation energies and ionization potentials mean absolute errors of 26 cm-1 and 59 cm-1, respectively. Correlated and uncorrelated molecular test calculations show deficiencies below 0.005 Å for the bond lengths and 3 N m-1 for the force constants. [ABSTRACT FROM AUTHOR]