QED effects on individual atomic orbital energies

Area of Science:

• Atomic Physics
• Quantum Electrodynamics (QED)
• Computational Chemistry

Background:

• Precise atomic calculations require accurate consideration of Quantum Electrodynamics (QED) effects.
• Self-energy and vacuum polarization are leading QED corrections crucial for atomic orbital energies.

Purpose of the Study:

• To calculate leading QED corrections (self-energy and vacuum polarization) for orbital energies in atoms with atomic numbers (Z) from 30 to 118.
• To analyze the combined QED and Breit contributions to orbital energy across different subshells (ns, np, nd).
• To investigate the Z-dependence of these contributions and their ratio.

Main Methods:

• Calculation of leading QED corrections (self-energy and vacuum polarization) for selected atoms.
• Analysis of the sum of QED and Breit contributions to orbital energy.
• Comparison of calculated QED contributions for valence ns-subshells with experimental first ionization potential data.

Main Results:

• For ns subshells, QED and Breit contributions are comparable in magnitude.
• For np and nd subshells, Breit contributions constitute the majority of the combined QED+Breit sum.
• The ratio of Breit to leading QED contributions for ns subshells shows minimal dependence on Z.
• Fitting coefficients derived can estimate QED effects on inner molecular orbitals.

Conclusions:

• QED and Breit corrections play significant roles in atomic orbital energies, with varying dominance across subshells.
• The findings provide insights into the Z-dependence of relativistic and QED effects in heavy atoms.
• The calculated QED contributions for valence ns-subshells show good agreement with experimental ionization potentials, validating the computational approach.