Relativistic and correlation effects for element 105 (hahnium, Ha): a comparative study of M and MO (M = Nb, Ta, Ha) using energy-adjusted ab initio pseudopotentials

Abstract

Nonrelativistic and quasirelativistic energy-adjusted ab initio pseudopotentials are presented for element 105 (hahnium, Ha) together with corresponding energy-optimized valence basis sets. The method of energy adjustment of pseudopotentials is extended to a two-component formalism and to multiconfiguration wave functions. The accuracy of the pseudopotential scheme is demonstrated by a comparison of atomic valence-only results to corresponding all-electron data. Atomic multiconfiguration self-consistent field and multireference configuration interaction calculations for M and M+ (M = Nb, Ta, Ha) are compared with available experimental data. Corresponding molecular calculations, which included spin-orbit coupling, have been performed for the lowlying states of H a 0 and are compared to the results from corresponding calculations of the lighter homologs NbO and TaO.

Seven‐Coordinate Luminophores: Brilliant Luminescence of Lanthanide Complexes with C3v Geometrical Structures

“…[50] The structure of the seven-and eight-coordinate Eu III complexes, Eu(tmh)3(tppo) and Eu(hfa)3(tppo)2, were optimized in the gas phase at the B3LYP-D3 [51,52] level with the Stuttgart RECP [53] and cc-pVDZ [54] basis sets for Eu and the other atoms, respectively. Then, the normal mode analysis of each molecule at the optimized structure was executed at the same level to obtain vibrational frequencies and IR intensities.…”

Chemistry of superheavy elements

“…This does not contradict theoretical calculations [205] showing a stronger tendency for Db to form oxide halides than Nb and Ta and could be viewed as an influence of relativistic effects in Db. A different theoretical approach showed a monotonic trend in the series of Nb, Ta and Db for the stability of monooxides [206].…”

Efficient quantum chemical valence-only treatments of lanthanide and actinide systems

“…Higher accuracy than with WB PPs was achieved for main group and transition metals with PPs derived from fullyrelativistic reference data [25,26,27,28,29,30,31,32,33,34]. However, except for U, such new MCDHF/DC+B- based PPs have not been adjusted for f elements yet.…”

“…Energy-consistent PPs in their most recent variant are adjusted to reference data taken from multi-configuration (MC) Dirac-Hartree-Fock (DHF) calculations using the Dirac-Coulomb (DC) Hamiltonian and including perturbative estimates of the Breit interaction (+B). Finite nucleus effects are usually also included, as well as sometimes higher order relativistic corrections [25,26,27,28,29,30,31,32,33,34].…”