title: Communications: On the relation between the scalar and tensor exchange-correlation kernels of the time-dependent density-functional theory.
abstract: The scalar f(xc) and tensor f(xc) exchange-correlation (xc) kernels are key ingredients of the time-dependent density functional theory and the time-dependent current density functional theory, respectively. We derive a comparatively simple relation between these two kernels under the assumption that the dynamic xc can be considered "weak." A calculation of the frequency-dependent dielectric function of silicon using this relation in conjunction with Vignale-Kohn f(xc) demonstrates a potential of our method to account for the dynamic many-body effects within the rigorous scheme of time-dependent density functional theory. Our formula provides a bridge between the scalar f(xc), which directly enters many applications, and the tensor f(xc) which, due to its locality in space, is much easier to approximate.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan. nazarov@gate.sinica.edu.tw
authors.forename: V U
authors.initials: VU
authors.lastname: Nazarov
authors.forename: G
authors.initials: G
authors.lastname: Vignale
authors.forename: Y-C
authors.initials: YC
authors.lastname: Chang