Decorrelation and exchange-correlation entropies in thermal ensembles

Kohn-Sham density functional theory approximations can suffer from a predisposition for weak correlation, whether used at zero temperature or for thermal ensembles. The finite-temperature strictly correlated electron approach, which re-references thermal density functional theory to use an infinitely interacting reference state for its formulation, can address this challenge. Doing so introduces a new free energy component, the decorrelation entropy. In this talk, we will examine how different reference system choices affect entropic contributions and how we can approach approximating entropic components for electronic systems in various regimes of density, temperature, and correlation strength.