Recent advances in reduced density matrix functional theory (RDMFT) and linear response
time-dependent reduced density matrix functional theory (TD-RDMFT) are reviewed. In …

In recent years, Natural Orbital Functional (NOF) theory has gained increasing significance
in quantum chemistry, successfully addressing one of the field's most challenging problems …

λ Δ, Π matrix is described herein, and used to reconstruct the two-particle reduced density
matrix (2-RDM). Then, we have derived a natural orbital functional, the Piris Natural Orbital …

Accurately predicting the spin splitting energy of chemical species is important for
understanding their reactivity and magnetic properties, but it is very challenging, especially …

The natural orbital functional (NOF) theory is briefly reviewed. The meaning of the top‐down
and bottom‐up approaches for the construction of a NOF is analyzed. A particular …

The cumulant expansion gives rise to an useful decomposition of the two‐matrix in which the
pair correlated matrix (cumulant) is disconnected from the antisymmetric product of the one …

The one-particle reduced density-matrix (1-RDM) functional theory is a promising alternative
to density-functional theory (DFT) that uses the 1-RDM rather than the electronic density as a …

Reduced density matrix functional theory (RDMFT), a promising direction in the problem of
describing strongly correlated systems, is currently limited by its explicit dependence on …

The convergence issues caused by the improper treatment of the ensemble N-
representability constraint have severely affected the applicability and reproducibility of …

We explore the hypercomplex Kohn-Sham (HCKS) formalism and develop a third exact
functional theory beyond the popular Kohn-Sham density functional theory (KS-DFT) and …