Accurate relativistic energy-consistent pseudopotentials for the superheavy elements 111 to 118 including quantum...

Area of Science:

• Computational Chemistry
• Relativistic Quantum Chemistry
• Atomic Physics

Background:

• Superheavy elements (SHEs) exhibit significant relativistic effects due to their high atomic numbers.
• Accurate theoretical models are essential for predicting the properties of SHEs, which are difficult to study experimentally.
• Existing pseudopotential methods require refinement to capture the complex electronic structures of SHEs.

Purpose of the Study:

• To develop and validate energy-consistent two-component semi-local pseudopotentials for superheavy elements (atomic numbers 111-118).
• To incorporate relativistic effects, including Breit and quantum electrodynamic corrections, into pseudopotential calculations.
• To ensure high accuracy for atomic property predictions of SHEs.

Main Methods:

• Adjustment of pseudopotentials using fully relativistic multi-configuration Dirac-Hartree-Fock (MCDHF) calculations.
• Inclusion of perturbative corrections for frequency-dependent Breit interaction and lowest-order quantum electrodynamics (QED).
• Optimization of primitive basis sets and application of general contraction schemes for valence basis sets.

Main Results:

• Developed pseudopotentials with mean absolute errors below 0.02 eV for atomic energy levels.
• Achieved finite basis set errors below 0.01-0.02 eV compared to the finite-difference Hartree-Fock limit.
• Validated results through Fock-space coupled-cluster calculations, showing good agreement with all-electron relativistic methods.

Conclusions:

• The developed pseudopotentials accurately describe the electronic structure of superheavy elements.
• Relativistic treatments beyond the Dirac-Coulomb level, including higher-order corrections, are necessary for SHEs.
• These pseudopotentials provide a reliable tool for future theoretical investigations of superheavy elements.