Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/98472
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Electronic excitations: density-functional versus many-body Green's-function approaches |
Autor: | Onida, Giovanni; Reining, Lucia; Rubio, Angel CSIC ORCID | Fecha de publicación: | 2002 | Editor: | American Physical Society | Citación: | Reviews of Modern Physics 74(2): 601-659 (2002) | Resumen: | Electronic excitations lie at the origin of most of the commonly measured spectra. However, the first-principles computation of excited states requires a larger effort than ground-state calculations, which can be very efficiently carried out within density-functional theory. On the other hand, two theoretical and computational tools have come to prominence for the description of electronic excitations. One of them, many-body perturbation theory, is based on a set of Green's-function equations, starting with a one-electron propagator and considering the electron-hole Green's function for the response. Key ingredients are the electron's self-energy σ and the electron-hole interaction. A good approximation for σ is obtained with Hedin's GW approach, using density-functional theory as a zero-order solution. First-principles G W calculations for real systems have been successfully carried out since the 1980s. Similarly, the electron-hole interaction is well described by the Bethe-Salpeter equation, via a functional derivative of σ. An alternative approach to calculating electronic excitations is the time-dependent density-functional theory (TDDFT), which offers the important practical advantage of a dependence on density rather than on multivariable Green's functions. This approach leads to a screening equation similar to the Bethe-Salpeter one, but with a two-point, rather than a four-point, interaction kernel. At present, the simple adiabatic local-density approximation has given promising results for finite systems, but has significant deficiencies in the description of absorption spectra in solids, leading to wrong excitation energies, the absence of bound excitonic states, and appreciable distortions of the spectral line shapes. The search for improved TDDFT potentials and kernels is hence a subject of increasing interest. It can be addressed within the framework of many-body perturbation theory: In fact, both the Green's functions and the TDDFT approaches profit from mutual insight. This review compares the theoretical and practical aspects of the two approaches and their specific numerical implementations, and presents an overview of accomplishments and work in progress. | Versión del editor: | http://dx.doi.org/10.1103/RevModPhys.74.601 | URI: | http://hdl.handle.net/10261/98472 | DOI: | 10.1103/RevModPhys.74.601 | Identificadores: | doi: 10.1103/RevModPhys.74.601 issn: 0034-6861 e-issn: 1539-0756 |
Aparece en las colecciones: | (CFM) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
Electronic excitations.pdf | 1,01 MB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
SCOPUSTM
Citations
3.241
checked on 20-abr-2024
WEB OF SCIENCETM
Citations
3.093
checked on 23-feb-2024
Page view(s)
885
checked on 23-abr-2024
Download(s)
3.782
checked on 23-abr-2024
Google ScholarTM
Check
Altmetric
Altmetric
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.