PARAM2
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] ( is not shown in this work and is implicitly set to 1.0), 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
- ↑ a b J. Klimeš, D. R. Bowler, and A. Michaelides, Phys. Rev. B 83, 195131 (2011).
- ↑ I. Hamada, Phys. Rev. B 89, 121103(R) (2014).
- ↑ a b c d D. Chakraborty, K. Berland, and T. Thonhauser, Next-Generation Nonlocal van der Waals Density Functional, J. Chem. Theory Comput. 16, 5893 (2020).
- ↑ a b J. Klimeš, D. R. Bowler, and A. Michaelides, J. Phys.: Condens. Matter 22, 022201 (2010).