Imaginary-Time Time-Dependent Density Functional Theory and Its Application for Robust Convergence of Electronic States
| Autor: | Efstratios Manousakis, Efthimios Kaxiras, Cedric Flamant, Grigory Kolesov |
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| Rok vydání: | 2019 |
| Předmět: |
Chemical Physics (physics.chem-ph)
Physics::Computational Physics Physics Condensed Matter - Materials Science 010304 chemical physics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Time-dependent density functional theory Computational Physics (physics.comp-ph) 01 natural sciences Imaginary time Computer Science Applications Electronic states Condensed Matter::Materials Science Physics - Chemical Physics 0103 physical sciences Convergence (routing) Physics::Atomic and Molecular Clusters Density functional theory Statistical physics Physics::Chemical Physics Physical and Theoretical Chemistry Ground state Physics - Computational Physics |
| Zdroj: | Journal of Chemical Theory and Computation. 15:6036-6045 |
| ISSN: | 1549-9626 1549-9618 |
| Popis: | Reliable and robust convergence to the electronic ground state within density functional theory (DFT) Kohn-Sham (KS) calculations remains a thorny issue in many systems of interest. In such cases, charge sloshing can delay or completely hinder the convergence. Here, we use an approach based on transforming the time-dependent DFT equations to imaginary time, followed by imaginary-time evolution, as a reliable alternative to the self-consistent field (SCF) procedure for determining the KS ground state. We discuss the theoretical and technical aspects of this approach and show that the KS ground state should be expected to be the long-imaginary-time output of the evolution, independent of the exchange-correlation functional or the level of theory used to simulate the system. By maintaining self-consistency between the single-particle wavefunctions and the electronic density throughout the determination of the stationary state, our method avoids the typical difficulties encountered in SCF. To demonstrate dependability of our approach, we apply it to selected systems which struggle to converge with SCF schemes. In addition, through the van Leeuwen theorem, we affirm the physical meaningfulness of imaginary time TDDFT, justifying its use in certain topics of statistical mechanics such as in computing imaginary time path integrals. 22 pages, 4 figures, 2 tables; changed order of theoretical section for clarity, text made more concise, tables/figures improved. Added additional references |
| Databáze: | OpenAIRE |
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