Towards timedependent currentdensityfunctional theory in the nonlinear regime
Abstract
TimeDependent DensityFunctional Theory (TDDFT) is a wellestablished theoretical approach to describe and understand irradiation processes in clusters and molecules. However, within the socalled adiabatic local density approximation (ALDA) to the exchangecorrelation (xc) potential, TDDFT can show insufficiencies, particularly in violently dynamical processes. This is because within ALDA the xc potential is instantaneous and is a local functional of the density, which means that this approximation neglects memory effects and longrange effects. A way to go beyond ALDA is to use TimeDependent CurrentDensityFunctional Theory (TDCDFT), in which the basic quantity is the current density rather than the density as in TDDFT. This has been shown to offer an adequate account of dissipation in the linear domain when the VignaleKohn (VK) functional is used. Here, we go beyond the linear regime and we explore this formulation in the time domain. In this case, the equations become very involved making the computation out of reach; we hence propose an approximation to the VK functional which allows us to calculate the dynamics in real time and at the same time to keep most of the physics described by the VK functional. We apply this formulation to the calculation of the timedependent dipole moment ofmore »
 Authors:
 Université de Toulouse, UPS, Laboratoire de Physique Théorique, IRSAMC, F31062 Toulouse Cedex (France)
 (France)
 (United Kingdom)
 Laboratoire de Physique Théorique, CNRS, IRSAMC, Université Toulouse III  Paul Sabatier and European Theoretical Spectroscopy Facility, 118 Route de Narbonne, 31062 Toulouse Cedex (France)
 Institut für Theoretische Physik, Universität Erlangen, Staudtstraße 7, D91058 Erlangen (Germany)
 Publication Date:
 OSTI Identifier:
 22416173
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; CORRELATIONS; CURRENT DENSITY; DENSITY FUNCTIONAL METHOD; DIPOLE MOMENTS; EXCITATION; IRRADIATION; MOLECULES; NONLINEAR PROBLEMS; POTENTIALS; TIME DEPENDENCE
Citation Formats
Escartín, J. M., CNRS, UMR5152, F31062 Toulouse Cedex, Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, Vincendon, M., Dinh, P. M., Suraud, E., CNRS, UMR5152, F31062 Toulouse Cedex, Romaniello, P., and Reinhard, P.G.. Towards timedependent currentdensityfunctional theory in the nonlinear regime. United States: N. p., 2015.
Web. doi:10.1063/1.4913291.
Escartín, J. M., CNRS, UMR5152, F31062 Toulouse Cedex, Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, Vincendon, M., Dinh, P. M., Suraud, E., CNRS, UMR5152, F31062 Toulouse Cedex, Romaniello, P., & Reinhard, P.G.. Towards timedependent currentdensityfunctional theory in the nonlinear regime. United States. doi:10.1063/1.4913291.
Escartín, J. M., CNRS, UMR5152, F31062 Toulouse Cedex, Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, Vincendon, M., Dinh, P. M., Suraud, E., CNRS, UMR5152, F31062 Toulouse Cedex, Romaniello, P., and Reinhard, P.G.. 2015.
"Towards timedependent currentdensityfunctional theory in the nonlinear regime". United States.
doi:10.1063/1.4913291.
@article{osti_22416173,
title = {Towards timedependent currentdensityfunctional theory in the nonlinear regime},
author = {Escartín, J. M. and CNRS, UMR5152, F31062 Toulouse Cedex and Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE and Vincendon, M. and Dinh, P. M. and Suraud, E. and CNRS, UMR5152, F31062 Toulouse Cedex and Romaniello, P. and Reinhard, P.G.},
abstractNote = {TimeDependent DensityFunctional Theory (TDDFT) is a wellestablished theoretical approach to describe and understand irradiation processes in clusters and molecules. However, within the socalled adiabatic local density approximation (ALDA) to the exchangecorrelation (xc) potential, TDDFT can show insufficiencies, particularly in violently dynamical processes. This is because within ALDA the xc potential is instantaneous and is a local functional of the density, which means that this approximation neglects memory effects and longrange effects. A way to go beyond ALDA is to use TimeDependent CurrentDensityFunctional Theory (TDCDFT), in which the basic quantity is the current density rather than the density as in TDDFT. This has been shown to offer an adequate account of dissipation in the linear domain when the VignaleKohn (VK) functional is used. Here, we go beyond the linear regime and we explore this formulation in the time domain. In this case, the equations become very involved making the computation out of reach; we hence propose an approximation to the VK functional which allows us to calculate the dynamics in real time and at the same time to keep most of the physics described by the VK functional. We apply this formulation to the calculation of the timedependent dipole moment of Ca, Mg and Na{sub 2}. Our results show trends similar to what was previously observed in model systems or within linear response. In the nonlinear domain, our results show that relaxation times do not decrease with increasing deposited excitation energy, which sets some limitations to the practical use of TDCDFT in such a domain of excitations.},
doi = {10.1063/1.4913291},
journal = {Journal of Chemical Physics},
number = 8,
volume = 142,
place = {United States},
year = 2015,
month = 2
}

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