References & Citations
Condensed Matter > Materials Science
Title: Hydrodynamic Tensor-DFT with correct susceptibility
(Submitted on 31 Dec 2006 (v1), last revised 4 Jan 2007 (this version, v2))
Abstract: In a previous work we developed a family of orbital-free tensor equations for DFT [J. Chem. Phys. 124, 024105 (2006)]. The theory is a combination of the coupled hydrodynamic moment equations hierarchy with a cumulant truncation of the one-body electron density matrix. A basic ingredient in the theory is how to truncate the series of equation of motion for the moments. In the original work we assumed that the cumulants vanish above a certain order (N). Here we show how to modify this assumption to obtain the correct susceptibilities. This is done for N=3, a level above the previous study. At the desired truncation level a few relevant terms are added, which, with the right combination of coefficients, lead to excellent agreement with the Kohn-Sham Lindhard susceptibilities for an uninteracting system. The approach is also powerful away from linear response, as demonstrated in a non-perturbative study of a jellium with a repulsive core, where excellent matching with Kohn-Sham simulations is obtained while the Thomas Fermi and von-Weiszacker methods show significant deviations. In addition, time-dependent linear response studies at the new N=3 level demonstrate our previous assertion that as the order of the theory is increased, new additional transverse sound modes appear mimicking the RPA transverse dispersion region.
Submission history
From: Igor Ovchinnikov V. [view email][v1] Sun, 31 Dec 2006 10:31:16 GMT (85kb)
[v2] Thu, 4 Jan 2007 18:02:44 GMT (85kb)
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