The quantum defect: the true measure of time-dependent density-functional results for atoms

TL;DR

This paper demonstrates that quantum defect theory provides a more accurate and insightful way to evaluate time-dependent density-functional calculations of Rydberg series in atoms than traditional transition energy analysis.

Contribution

It introduces the application of quantum defect theory to assess and interpret time-dependent density-functional results for Rydberg states in atoms.

Findings

Quantum defect offers a better measure of calculation accuracy.

Quantum defect analysis clarifies the behavior of Rydberg series.

Results improve understanding of density-functional methods for atomic spectra.

Abstract

Quantum defect theory is applied to (time-dependent) density-functional calculations of Rydberg series for closed shell atoms: He, Be, and Ne. The performance and behavior of such calculations is much better quantified and understood in terms of the quantum defect, rather than transition energies.