LIBXC1: Difference between revisions

Revision as of 14:38, 20 December 2021

LIBXC1/LIBXC2 = [integer] or string

Description: LIBXC1/LIBXC2 specify the functionals from the library of exchange-correlation functionals that one wants to use.

LIBXC1 and LIBXC2 can be either integers (e.g, 101 for PBE exchange) or strings (e.g., GGA_X_PBE). The list

Cite error: <ref> tag with name "lehtola:sx:18" defined in <references> has group attribute "" which does not appear in prior text.

Related Tags and Sections

AGGAX, AGGAC, ALDAC, LHFCALC, hybrid functionals, settings for specific hybrid functionals

Examples that use this tag

@@ Line 5: / Line 5: @@
 LIBXC1 and LIBXC2 can be either integers (e.g, 101 for PBE exchange) or strings (e.g., GGA_X_PBE). The list
-The amount of LDA correlation included in the hybrid functional can be specified through the {{TAG|ALDAC}}-tag.
-The amount of gradient correction to the exchange and the correlation contributions can be set indepently, however (some [[specific_hybrid_functionals|popular hybride functionals]] for instance use only 0.8 of the gradient contribition to the exchange). The GGA flags {{TAG|AGGAX}} and {{TAG|AGGAC}} are only used if GGA is already selected (for LDA type calculations no gradient correction will be added regardless of values is used for {{TAG|AGGAX}} and {{TAG|AGGAC}}).
-'''Note''': The defaults are chosen such that the hybrid PBE0 functional is selected for PBE pseudopotentials (the PBE0 functional contains 25% of the exact exchange, and  75% of the PBE exchange, and 100% of the PBE correlation  energy). The resulting expression for the exchange-correlation energy then takes the following simple form:
-<math>
-E_{\mathrm{xc}}^{\mathrm{PBE0}}=\frac{1}{4}~E_{\mathrm{x}}~+
-~\frac{3}{4}~ E_{\mathrm{x}}^{\mathrm{PBE}}
-+~E_{\mathrm{c}}^{\mathrm{PBE}}
-</math>
-Other sensible values are of course {{TAG|AEXX}}=1.0 (full Hartree-Fock type calculations). In this case, VASP also automatically selects {{TAG|ALDAC}}=0.0 and {{TAG|AGGAC}}=0.0, to avoid the addition of a (semi-local) correlation energy.
-A comprehensive evaluation of the performance of the PBE0 functional, as compared to PBE, can be found in Ref. <ref name="paier:jcp:05"/>.
 <references>
-<ref name="paier:jcp:05">[https://aip.scitation.org/doi/10.1063/1.1926272 J. Paier, R. Hirschl, M. Marsman, and G. Kresse, J. Chem. Phys. 122, 234102 (2005).]</ref>
+<ref name="lehtola:sx:18">[https://doi.org/10.1016/j.softx.2017.11.002 S. Lehtola, C. Steigmann, M. J. T.  Oliveira, and M. A. L. Marques, SoftwareX 7, 1 (2018).]</ref>
 </references>