Reduced density matrix functional theory (RDMFT) and linear response time-dependent RDMFT (TD-RDMFT)

K Pernal, KJH Giesbertz - Density-Functional Methods for Excited States, 2016 - Springer
Recent advances in reduced density matrix functional theory (RDMFT) and linear response
time-dependent reduced density matrix functional theory (TD-RDMFT) are reviewed. In …

One-body reduced density-matrix functional theory in finite basis sets at elevated temperatures

KJH Giesbertz, M Ruggenthaler - Physics Reports, 2019 - Elsevier
In this review we provide a rigorous and self-contained presentation of one-body reduced
density-matrix (1RDM) functional theory. We do so for the case of a finite basis set, where …

Foundation of one-particle reduced density matrix functional theory for excited states

J Liebert, F Castillo, JP Labbé… - Journal of chemical …, 2021 - ACS Publications
In Phys. Rev. Lett. 2021, 127, 023001 a reduced density matrix functional theory (RDMFT)
was proposed for calculating energies of selected eigenstates of interacting many-Fermion …

Exploiting the Hessian for a Better Convergence of the SCF-RDMFT Procedure

NG Cartier, KJH Giesbertz - Journal of chemical theory and …, 2024 - ACS Publications
One-body reduced density matrix functional theory provides an alternative to density
functional theory, which is able to treat static correlation while kee** a relatively low …

Natural occupation numbers: When do they vanish?

KJH Giesbertz, R van Leeuwen - The Journal of Chemical Physics, 2013 - pubs.aip.org
The non-vanishing of the natural orbital (NO) occupation numbers of the one-particle density
matrix of many-body systems has important consequences for the existence of a density …

Implications of the unitary invariance and symmetry restrictions on the development of proper approximate one-body reduced-density-matrix functionals

KJH Giesbertz - Physical Review A, 2020 - APS
In many of the approximate functionals in one-body reduced-density-matrix (1RDM)
functional theory, the approximate two-body reduced density matrix (2RDM) in the natural …

Response calculations based on an independent particle system with the exact one-particle density matrix: Excitation energies

KJH Giesbertz, OV Gritsenko… - The Journal of chemical …, 2012 - pubs.aip.org
Adiabatic response time-dependent density functional theory (TDDFT) suffers from the
restriction to basically an occupied→ virtual single excitation formulation. Adiabatic time …

Are natural orbitals useful for generating an efficient expansion of the wave function?

KJH Giesbertz - Chemical Physics Letters, 2014 - Elsevier
We investigate whether the natural orbitals (NOs) minimize∥ Ψ-Φ∥ 2, where Ψ is a wave
function and Φ is a full configuration interaction (CI) approximation to Ψ in a reduced basis …

Time-dependent renormalized natural orbital theory applied to the two-electron spin-singlet case: Ground state, linear response, and autoionization

M Brics, D Bauer - Physical Review A—Atomic, Molecular, and Optical …, 2013 - APS
Favorably scaling numerical time-dependent many-electron techniques such as time-
dependent density functional theory (TDDFT) with adiabatic exchange-correlation potentials …

Secondary Kinetic Peak in the Kohn–Sham Potential and Its Connection to the Response Step

S Giarrusso, R Neugarten, EJ Baerends… - Journal of chemical …, 2022 - ACS Publications
We consider a prototypical 1D model Hamiltonian for a stretched heteronuclear molecule
and construct individual components of the corresponding KS potential, namely, the kinetic …