Discontinuities of the exchange-correlation kernel and charge-transfer excitations in time-dependent density functional theory

Autor:	Hellgren, M., Gross, E. K. U.
Rok vydání:	2011
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics Physics - Atomic Physics Physics - Chemical Physics
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevA.85.022514
Popis:	We identify the key property that the exchange-correlation (XC) kernel of time-dependent density functional theory must have in order to describe long-range charge-transfer excitations. We show that the discontinuity of the XC potential as a function of particle number induces a space -and frequency-dependent discontinuity of the XC kernel which diverges as $r\to\infty$. In a combined donor-acceptor system, the same discontinuity compensates for the vanishing overlap between the acceptor and donor orbitals, thereby yielding a finite correction to the Kohn-Sham eigenvalue differences. This mechanism is illustrated to first order in the Coulomb interaction. Comment: 6 pages, 3 figures (expanded version, accepted in Phys. Rev. A)
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1108.3100 Zobrazit plný text záznamu View this record from Arxiv