Time Evolution: Difference between revisions

Revision as of 11:26, 28 March 2018

Description: ALGO= timeev calculates the frequency dependent dielectric matrix after the electronic ground state has been determined using the time evolution algorithm (only available in vasp.6)

The timepropagation algorithm applies an short electric field puls in time, and then follows the evolution of the dipole moments. The Green-Kubo relation then allows to calculate the frequency dependent dielectric response function from the time evolution of the dipole moments

VASP posses multiple other routines to calculate the frequency dependent dielectric function. The simplest approach uses the independent particle approximation (LOPTICS=.TRUE. Furthermore, one can use ALGO = TDHF (BSE calculations equivalent to solving the Casida equation), ALGO = GW (GW calculations). For standard DFT, the timeevolution algorithm is usually fastest, whereas for hybrid functionals ALGO = TDHF is usually faster.

Related Tags and Sections

CSHIFT, LADDER, LHARTREE, NBANDSV, NBANDSO

BSE calculations

References

Cite error: <ref> tag with name "kubo:prb:57" defined in <references> has group attribute "" which does not appear in prior text.

Contents

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 Description: {{TAG|ALGO}}= timeev calculates the frequency dependent dielectric matrix after the electronic ground state has been determined using the time evolution algorithm (only available in vasp.6)
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+The timepropagation algorithm applies an short electric field puls in time, and
+then follows the evolution of the dipole moments. The Green-Kubo relation
+then allows to calculate the frequency dependent dielectric response function
+from the time evolution of the dipole moments
 VASP posses multiple other routines to calculate the frequency dependent dielectric function.
-Specifically, one can use {{TAG|ALGO}} = TDHF ([[BSE calculations]] equivalent to solving the Casida equation), {{TAG|ALGO}} = GW ([[GW calculations]]). For standard DFT, the timeevolution algorithm is
+The simplest approach uses the independent particle approximation ({{TAG|LOPTICS}}=.TRUE.
+Furthermore, one can use {{TAG|ALGO}} = TDHF ([[BSE calculations]] equivalent to solving the Casida equation), {{TAG|ALGO}} = GW ([[GW calculations]]).
+For standard DFT, the timeevolution algorithm is
 usually fastest, whereas for hybrid functionals {{TAG|ALGO}} = TDHF  is
 usually faster.
@@ Line 19: / Line 27: @@
 == References ==
 <references>
-<ref name="gajdos:prb:06">[http://link.aps.org/doi/10.1103/PhysRevB.73.045112 M. Gajdoš, K. Hummer, G. Kresse, J. Furthmüller, and F. Bechstedt, Phys. Rev. B 73, 045112 (2006).]</ref>
+<ref name="kubo:prb:57">[http://journals.jps.jp/doi/10.1143/JPSJ.12.570
+Ryogo Kubo, Statistical-Mechanical Theory of Irreversible Processes. I. General Theory and Simple Applications to Magnetic and Conduction Problems. In: Journal of the Physical Society of Japan. Band 12, Nr.6, 15. Juni 1957, S.570–586, doi:10.1143/JPSJ.12.57].</ref>
 </references>
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