Validity of the inverse-GKS spectral relation for strongly correlated systems

Determine whether the exact-exchange-fraction dependence of occupied generalized Kohn–Sham eigenvalues and their relation to vertical ionization energies, established for weakly correlated molecules, remains valid for strongly correlated systems.

Background

The paper studies inverse generalized Kohn–Sham calculations at fixed, near-exact CCSD densities for several weakly correlated closed-shell molecules. By varying the exact-exchange fraction while holding the density fixed, it identifies a systematic dependence of the occupied generalized Kohn–Sham spectrum on the one-particle operator.

The authors explicitly restrict the conclusions to weakly correlated systems because the approximation used for the multiplicative remainder potential is reported to fail for stretched, strongly correlated systems. Whether the observed exact-exchange dependence and spectral behavior extend to that regime is left unresolved.

References

Whether the $\alpha$-dependence reported here is valid for strongly correlated systems is therefore an open question.

— Vertical ionization energies from inverse generalized Kohn-Sham calculations at fixed electron density  (2610.22024 - Subramanian et al., 15 Oct 2026) in Discussion, Section 6 (paragraph beginning “The results presented here are valid for weakly correlated systems”)