Journal ArticleDOI
On the determination of excitation energies using density functional theory
David J. Tozer,Nicholas C. Handy +1 more
TLDR
In this paper, the use of time-dependent density functional theory (TDDFT) is considered for the determination of electronic excitation energies, and the authors highlight the problems with Rydberg excitations arising from neglect of the integer discontinuity in the potential.Abstract:
The use of time-dependent density functional theory (TDDFT) is considered for the determination of electronic
excitation energies. Using beryllium and methylene as examples, we highlight (i) problems with Rydberg excitations
arising from neglect of the integer discontinuity in the potential; (ii) the absence of pure double excitations
in calculations using conventional exchange-correlation functionals; (iii) quantitative differences
between excitation energies determined using TDDFT and the ‘delta SCF’ method; (iv) non-additivity of excitation
energies calculated using TDDFT from different electronic states; (v) an apparent failure to predict single excitations
to states that are lower than the reference
states and (vi)
the difference in quality
between excitations to singlet and triplet states.read more
Citations
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Journal ArticleDOI
Quantum mechanical continuum solvation models.
TL;DR: This paper presents a meta-modelling procedure called "Continuum Methods within MD and MC Simulations 3072", which automates the very labor-intensive and therefore time-heavy and expensive process of integrating discrete and continuous components into a discrete-time model.
Journal ArticleDOI
Orbital-dependent density functionals: Theory and applications
Stephan Kümmel,Leeor Kronik +1 more
TL;DR: In this article, the authors provide a perspective on the use of orbital-dependent functionals, which is currently considered one of the most promising avenues in modern density-functional theory.
Journal ArticleDOI
Time-dependent density functional theory: Past, present, and future
TL;DR: This article discusses how TDDFT is much broader in scope, and yields predictions for many more properties, and discusses some of the challenges involved in making accurate predictions for these properties.
Journal ArticleDOI
On the prediction of band gaps from hybrid functional theory
TL;DR: In this paper, a hybrid scheme is used to predict the band gaps of a variety of materials, including silicon, and the electronic structure of silicon is examined in some detail and comparisons with alternative theories are made.
Journal ArticleDOI
Double excitations within time-dependent density functional theory linear response
TL;DR: This work derives the exact frequency-dependent kernel when a double excitation mixes with a single excitation, well separated from the other excitations, in the limit that the electron--electron interaction is weak.
References
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Journal ArticleDOI
Treatment of electronic excitations within the adiabatic approximation of time dependent density functional theory
TL;DR: In this paper, the three-parameter Lee-Yang-Parr (B3LYP) functional was used to compute low-lying electronic excitations of N2, ethylene, formaldehyde, pyridine and porphin.
Journal ArticleDOI
Molecular excitation energies to high-lying bound states from time-dependent density-functional response theory: Characterization and correction of the time-dependent local density approximation ionization threshold
TL;DR: In this paper, the performance of time-dependent density-functional response theory (TD-DFRT) for the calculation of high-lying bound electronic excitation energies of molecules is evaluated.
Journal ArticleDOI
Density-Functional Theory for Fractional Particle Number: Derivative Discontinuities of the Energy
TL;DR: The Hohenberg-Kohn theorem was extended to fractional electron number for an isolated open system described by a statistical mixture in this article, and the curve of lowest average energy was found to be a series of straight line segments with slope discontinuities at integral $N.
Journal ArticleDOI
Development and assessment of new exchange-correlation functionals
TL;DR: In this article, the generalized gradient approximation (GGA) exchange-correlation energy function was developed using a least-squares procedure involving numerical exchange correlation potentials and experimental energetics and nuclear gradients.
Journal ArticleDOI
Excitation energies from time-dependent density-functional theory.
TL;DR: In this article, a density-functional approach to calculate the excitation spectrum of many-electron systems is proposed, which can rigorously express the full linear density response of the interacting system, which has poles at the exact excitation energies, in terms of the response function of the noninteracting (Kohn-Sham) system and a frequency-dependent exchange-correlation kernel.