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Related papers: Time-Dependent Local Density Approximation for Col…

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Quantum embedding schemes have the potential to significantly reduce the computational cost of first principles calculations, whilst maintaining accuracy, particularly for calculations of electronic excitations in complex systems. In this…

Materials Science · Physics 2022-03-10 Joseph C. A. Prentice

We investigate the time an electronic excitation travels in a supermolecular setup using a measurement process in an open quantum-system framework. The approach is based on the stochastic Schr\"odinger equation and uses a Hamiltonian from…

Materials Science · Physics 2013-12-09 Dirk Hofmann , Heiko Appel , Massimiliano Di Ventra , Stephan Kümmel

We recently introduced the dynamical cluster approximation(DCA), a new technique that includes short-ranged dynamical correlations in addition to the local dynamics of the dynamical mean field approximation while preserving causality. The…

Strongly Correlated Electrons · Physics 2009-10-31 M. H. Hettler , M. Mukherjee , M. Jarrell , H. R. Krishnamurthy

Most applications of time-dependent density-functional theory (TDDFT) use the adiabatic local-density approximation (ALDA) for the dynamical exchange-correlation potential Vxc(r,t). An exact (i.e., nonadiabatic) extension of the…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 C. A. Ullrich

Isoscalar collective modes in a relativistic meson-nucleon system are investigated in the framework of the time-dependent Thomas-Fermi method. The energies of the collective modes are determined by solving consistently the dispersion…

Nuclear Theory · Physics 2008-11-26 C. da Providência , L. Brito , J. da Providência , M. Nielsen , X. Viñas

Collective motion is a manifestation of emergent phenomena in medium-heavy and heavy nuclei. A relatively large number of constituent nucleons contribute coherently to nuclear excitations (vibrations, rotations) that are characterized by…

Nuclear Theory · Physics 2022-03-18 Z. P. Li , D. Vretenar

Density functional theory is a preferred microscopic method for calculation of nuclear properties over the whole nuclear chart. Besides ground-state properties, which are calculated by Hartree-Fock theory, nuclear excitations can be…

Nuclear Theory · Physics 2020-06-02 Anton Repko

An adiabatic approximation to the selfconsistent collective coordinate method is formulated in order to describe large amplitude collective motions in superconducting nuclei on the basis of the time-dependent Hartree-Fock-Bogoliubov…

Nuclear Theory · Physics 2009-11-06 M. Matsuo , T. Nakatsukasa , K. Matsuyanagi

We present an efficient perturbative method to obtain both static and dynamic polarizabilities and hyperpolarizabilities of complex electronic systems. This approach is based on the solution of a frequency dependent Sternheimer equation,…

Materials Science · Physics 2009-11-13 Xavier Andrade , Silvana Botti , Miguel A. L. Marques , Angel Rubio

Cluster analysis which focuses on the grouping and categorization of similar elements is widely used in various fields of research. Inspired by the phenomenon of atomic fission, a novel density-based clustering algorithm is proposed in this…

Machine Learning · Computer Science 2020-04-28 Shizhan Lu

We present an implementation of time-dependent density-functional theory (TDDFT) in the linear response formalism enabling the calculation of low energy optical absorption spectra for large molecules and nanostructures. The method avoids…

We introduce a microscopic approach for calculating the excitation energies of systems formed during heavy-ion collisions. The method is based on time-dependent Hartree-Fock (TDHF) theory and allows the study of the excitation energy as a…

Nuclear Theory · Physics 2009-10-29 A. S. Umar , V. E. Oberacker , J. A. Maruhn , P. -G. Reinhard

We report the formulation of a new, cost-effective approximation method in the time-dependent optimized coupled-cluster (TD-OCC) framework [T. Sato et al., J. Chem. Phys. 148, 051101 (2018)] for first-principles simulations of multielectron…

Chemical Physics · Physics 2022-08-11 Himadri Pathak , Takeshi Sato , Kenichi L. Ishikawa

The local density approximation (LDA) constructed through quantum Monte Carlo calculations of the homogeneous electron gas (HEG) is the most common approximation to the exchange-correlation functional in density functional theory. We…

Other Condensed Matter · Physics 2021-01-15 Mike Entwistle , Matthew Hodgson , Jack Wetherell , Bradley Longstaff , James Ramsden , Rex Godby

The Hohenberg-Kohn density functional was long ago shown to reduce to the Thomas-Fermi approximation in the non-relativistic semiclassical (or large-$Z$) limit for all matter, i.e, the kinetic energy becomes local. Exchange also becomes…

Materials Science · Physics 2016-08-24 Kieron Burke , Antonio Cancio , Tim Gould , Stefano Pittalis

We present an embedding approach to treat local electron correlation effects in periodic environments. In a single, consistent framework, our plane-wave based scheme embeds a local high-level correlation calculation (here Coupled Cluster…

Chemical Physics · Physics 2021-01-07 Tobias Schäfer , Florian Libisch , Georg Kresse , Andreas Grüneis

Collective effects in the level density are not well understood, and including these effects as enhancement factors to the level density does not produce sufficiently consistent predictions of observables. Therefore, collective effects are…

Nuclear Theory · Physics 2014-06-19 Bora Canbula , Ramazan Bulur , Deniz Canbula , Halil Babacan

A new alternate method for evaluating linear response theory is formally developed, and results are presented. This method involves the time-evolution of the system using TDHF and is constructed directly on top of a static Hartree-Fock…

Nuclear Theory · Physics 2009-11-11 A. S. Umar , V. E. Oberacker

Time-dependent density-functional theory (TDDFT) treats dynamical exchange and correlation (xc) via a single-particle potential, Vxc(r,t), defined as a nonlocal functional of the density n(r',t'). The popular adiabatic local-density…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 C. A. Ullrich , I. V. Tokatly

In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach,…

Nuclear Theory · Physics 2015-02-16 V. E. Oberacker , A. S. Umar
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