PARAM1

From VASP Wiki

PARAM1 = [real]
Default: PARAM1 = 0.1234 

Description: [math]\displaystyle{ \mu }[/math] for GGA=MK, [math]\displaystyle{ \beta }[/math] for GGA=BO.


The PARAM1 tag determines the value corresponding to different parameters depending on the GGA functional that is chosen:

  • [math]\displaystyle{ \mu }[/math] in the optB86b[1], B86R[2], and DF3-opt2[3] exchange functionals, which have the same analytical form and correspond to GGA=MK. PARAM1 should in principle be set to 0.1234 for the optB86b-vdW nonlocal functional[1] or to [math]\displaystyle{ 10/81\approx0.1234568 }[/math] for the rev-vdW-DF2[2] and vdW-DF3-opt2[3] nonlocal functionals.
  • [math]\displaystyle{ \beta }[/math] in the optB88[4] exchange functional or [math]\displaystyle{ \mu/\kappa }[/math] in the DF3-opt1[3] exchange functional, which have the same analytical form and correspond to GGA=BO. PARAM1 should in principle be set to [math]\displaystyle{ 0.22/1.2\approx0.1833333333 }[/math] for the optB88-vdW nonlocal functional[4] or to [math]\displaystyle{ (10/81)/1.1\approx0.1122334456 }[/math] for the vdW-DF3-opt1[3] nonlocal functional.

The complete INCAR file for the nonlocal van der Waals functionals mentioned above can be found at Nonlocal vdW-DF functionals.

Related tags and articles

PARAM2, GGA, Nonlocal vdW-DF functionals

Examples that use this tag

References