Journal ArticleDOI
Time-Dependent Density Functional Tight Binding: New Formulation and Benchmark of Excited States.
TLDR
A new formulation of time-dependent density functional tight binding (TD-DFTB) is reported, derived from the application of the linear response theory to the ground state DFTB Hamiltonian, without the introduction of additional parameters for the description of the excited states.Abstract:
A new formulation of time-dependent density functional tight binding (TD-DFTB) is reported in this paper. It is derived from the application of the linear response theory to the ground state DFTB Hamiltonian, without the introduction of additional parameters for the description of the excited states. The method is validated for several sets of organic compounds, against the best theoretical estimates from the literature, density functional theory, semiempirical methods, and experimental data. The comparison shows that TD-DFTB gives reliable results both for singlet and triplet excitation energies. In addition, the application of TD-DFTB to open-shell systems shows promising results.read more
Citations
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Journal ArticleDOI
TD-DFT benchmarks: A review
TL;DR: In this article, the authors review TD-DFT benchmarks that have been performed during the last decade and present both the different strategies used to assess the functionals and the main results obtained in terms of accuracy.
Journal ArticleDOI
DFTB+, a software package for efficient approximate density functional theory based atomistic simulations
Benjamin Hourahine,Bálint Aradi,Volker Blum,Franco P. Bonafé,A. Buccheri,Cristopher Camacho,C. Cevallos,M. Y. Deshaye,Traian Dumitrica,Adriel Dominguez,Sebastian Ehlert,Marcus Elstner,T. van der Heide,Jan Hermann,Stephan Irle,Julian J. Kranz,Christof Köhler,Tim Kowalczyk,Tomáš Kubař,I. S. Lee,Vitalij Lutsker,Reinhard J. Maurer,Seung Kyu Min,Izaac Mitchell,Christian F. A. Negre,Thomas A. Niehaus,Anders M. N. Niklasson,Alister J. Page,Alessandro Pecchia,G. Penazzi,M. P. Persson,Jan Řezáč,Cristián G. Sánchez,Michael Sternberg,Martin Stöhr,F. Stuckenberg,Alexandre Tkatchenko,Victor Yu,Thomas Frauenheim +38 more
TL;DR: An overview of the recently developed capabilities of the DFTB+ code is given, demonstrating with a few use case examples, and the strengths and weaknesses of the various features are discussed, to discuss on-going developments and possible future perspectives.
Journal ArticleDOI
A Mountaineering Strategy to Excited States: Highly Accurate Reference Energies and Benchmarks.
Pierre-François Loos,Anthony Scemama,Aymeric Blondel,Yann Garniron,Michel Caffarel,Denis Jacquemin +5 more
TL;DR: By systematically increasing the order of the CC expansion, the number of determinants in the CI expansion as well as the size of the one-electron basis set, the possibility to use basis set extrapolation approaches so as to tackle more easily larger compounds is discussed.
Journal ArticleDOI
Benchmarking the Bethe-Salpeter Formalism on a Standard Organic Molecular Set.
TL;DR: It is shown that a simple self-consistent scheme at the GW level, with an update of the quasiparticle energies, not only leads to a much better agreement with reference values, but also significantly reduces the impact of the starting DFT functional.
Journal ArticleDOI
A Mountaineering Strategy to Excited States: Highly Accurate Energies and Benchmarks for Medium Sized Molecules
Pierre-François Loos,Filippo Lipparini,Martial Boggio-Pasqua,Anthony Scemama,Denis Jacquemin +4 more
TL;DR: The present contribution gathers a large, diverse and accurate set of more than 200 highly-accurate transition energies for states of various natures (valence, Rydberg, singlet, triplet, n-pi*, pi-pi*...) to benchmark a series of popular methods for excited state calculations.
References
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Development and use of quantum mechanical molecular models. 76. AM1: a new general purpose quantum mechanical molecular model
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Density-Functional Theory for Time-Dependent Systems
Erich Runge,E. K. U. Gross +1 more
TL;DR: In this article, a time-dependent version of density functional theory was proposed to deal with the non-perturbative quantum mechanical description of interacting many-body systems moving in a very strong timedependent external field.
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Ground States of Molecules. 38. The MNDO Method. Approximations and Parameters
Michael J. S. Dewar,Walter Thiel +1 more
Journal ArticleDOI
An efficient implementation of time-dependent density-functional theory for the calculation of excitation energies of large molecules
TL;DR: In this paper, time-dependent density-functional (TDDFT) methods are applied within the adiabatic approximation to a series of molecules including C70, and they provide an efficient approach for treating frequency-dependent response properties and electronic excitation spectra of large molecules.
Journal ArticleDOI
Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties
Marcus Elstner,Marcus Elstner,D. Porezag,G. Jungnickel,J. Elsner,M. Haugk,Th. Frauenheim,Sándor Suhai,Gotthard Seifert +8 more
TL;DR: In this paper, an extension of the tight-binding (TB) approach to improve total energies, forces, and transferability is presented. The method is based on a second-order expansion of the Kohn-Sham total energy in density-functional theory (DFT) with respect to charge density fluctuations.