LIBXC1 Pn

LIBXC1_Pn = [real] 

Description: LIBXC1_Pn and LIBXC2_Pn, where $n=1, 2, ...$ allow to specify the values of the parameters of the functionals implemented in Libxc that are called with LIBXC1 and LIBXC2, respectively.

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For many functionals implemented in the library of exchange-correlation functionals Libxc it is possible to modify the parameters if one does not want to use the default values. If a functional from Libxc has parameters that can be modified, then they are listed in OUTCAR below "Parameters of Libxc functionals:" as P$n$ ($n=1, 2, ...$).

An example is given below for the GGA PBE functional where the parameters $\mu=0.21951$ in exchange and $\beta=0.066725$ in correlation are changed to $\mu=10/81$ and $\beta=0.046$ to get the PBEsol functional (of course, the simpler way to use PBEsol from Libxc without having to specify the parameters is to call it directly with LIBXC1=116 and LIBXC2=133).

GGA = LIBXC
LIBXC1 = 101
LIBXC2 = 130
LIBXC1_P2 = 0.12345679
LIBXC2_P1 = 0.046

Libxc also provides the semilocal component of hybrid functionals. These are the functionals with a tag that contains HYB on the Libxc website, and important points concerning their parameters are the following:

• The mixing parameter between the semilocal and exact exchange is one of the parameters LIBXC1_Pn, and can therefore be modified.
• For HYB_GGA_XC_PBEH, HYB_GGA_XC_B1WC, HYB_GGA_XC_HSE03, HYB_GGA_XC_HSE06, HYB_GGA_XC_HSE12, and HYB_GGA_XC_HSE12S, the value of AEXX will be used and automatically be passed to the corresponding parameter in Libxc. However, if the corresponding parameter LIBXC1_Pn is specified in INCAR, then AEXX will be overruled by LIBXC1_Pn.
• However, if the

Related Tags and Sections

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

Examples that use this tag

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