PARAM2: Difference between revisions

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Description: The {{TAG|PARAM2}} tag determines the value corresponding to different parameters depending on the {{TAG|GGA}} functional that is chosen:
Description: The {{TAG|PARAM2}} tag determines the value corresponding to different parameters depending on the {{TAG|GGA}} functional that is chosen:
*<math>\mu</math> in the exchange GGA optB86b{{cite|klimes:prb:2011}}, B86R{{cite|hamada:prb:2014}}, and DF3-opt2{{cite|chakraborty:jctc:2020}}, which have the same analytical form and correspond to {{TAG|GGA}}=MK. {{TAG|PARAM1}} should in principle be set to 0.1234 for the nonlocal optB86b-vdW functional{{cite|klimes:prb:2011}} or to <math>10/81\approx0.1234567</math> for the rev-vdW-DF2{{cite|hamada:prb:2014}} and vdW-DF3-opt2{{cite|chakraborty:jctc:2020}} (available as of VASP.6.5.0) functionals.
*<math>\kappa</math> in the exchange GGA optB86b{{cite|klimes:prb:2011}}, B86R{{cite|hamada:prb:2014}}, and DF3-opt2{{cite|chakraborty:jctc:2020}}, which have the same analytical form and correspond to {{TAG|GGA}}=MK. {{TAG|PARAM2}} should in principle be set to 1.0 for the nonlocal optB86b-vdW functional{{cite|klimes:prb:2011}} or to <math>0.58</math> for the vdW-DF3-opt2{{cite|chakraborty:jctc:2020}} functionals.
*<math>\beta</math> in the exchange GGA optB88{{cite|klimes:jpcm:2010}} or <math>\mu/\kappa</math> in DF3-opt1{{cite|chakraborty:jctc:2020}}, which have the same analytical form and correspond to {{TAG|GGA}}=BO. {{TAG|PARAM1}} should in principle be set to 0.1833333333 for the nonlocal optB88-vdW functional{{cite|klimes:jpcm:2010}} or to <math>(10/81)/1.1\approx0.1122334456</math> for the vdW-DF3-opt1{{cite|chakraborty:jctc:2020}} (available as of VASP.6.5.0) functional.
*<math>\beta</math> in the exchange GGA optB88{{cite|klimes:jpcm:2010}} or <math>\mu/\kappa</math> in DF3-opt1{{cite|chakraborty:jctc:2020}}, which have the same analytical form and correspond to {{TAG|GGA}}=BO. {{TAG|PARAM1}} should in principle be set to 0.1833333333 for the nonlocal optB88-vdW functional{{cite|klimes:jpcm:2010}} or to <math>(10/81)/1.1\approx0.1122334456</math> for the vdW-DF3-opt1{{cite|chakraborty:jctc:2020}} (available as of VASP.6.5.0) functional.
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Revision as of 10:26, 30 January 2024

PARAM2 = [real]
Default: PARAM2 = 1.0 

Description: The PARAM2 tag determines the value corresponding to different parameters depending on the GGA functional that is chosen:

  • in the exchange GGA optB86b[1], B86R[2], and DF3-opt2[3], which have the same analytical form and correspond to GGA=MK. PARAM2 should in principle be set to 1.0 for the nonlocal optB86b-vdW functional[1] or to for the vdW-DF3-opt2[3] functionals.
  • in the exchange GGA optB88[4] or in DF3-opt1[3], which have the same analytical form and correspond to GGA=BO. PARAM1 should in principle be set to 0.1833333333 for the nonlocal optB88-vdW functional[4] or to for the vdW-DF3-opt1[3] (available as of VASP.6.5.0) functional.

Note that PARAM2 should be set to 1.0 (the default) for the nonlocal optB86b-vdW functional, to 0.711357 for the nonlocal rev-vdW-DF2 functional or to 0.22 for the nonlocal optB88-vdW functional.

Related tags and articles

PARAM1, GGA, Nonlocal vdW-DF functionals

Examples that use this tag