PARAM2
PARAM2 = [real]
Default: PARAM2 = 1.0
Description: The PARAM2 tag determines the value corresponding to either in the exchange GGA optB86b[1]/B86R[2] (GGA=MK) or in the exchange GGA optB88[3] (GGA=BO).
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