[Pw_forum] vdW functional in Quantum-Espresso

[WF]

There are large changes in vdW functional part between version 4.3 and 4.3.1
or later. First, the vdW functional is put in GGA correlation part in
funct.f90 in 4.3, but in an independent part (non-local part) in funct.f90
in 4.3.1. Second, the ld1.x refuse to generate pseudo-potential for
functional containing vdW part like vdW-DF in 4.3.1 for it is non-local but
it is possible to generate something in 4.3. So I have some question about
vdW functional.

 

1.       In 4.3, does vdW-DF, or "sla+pw+rpb+vdw" as 1/4/4/9 imply the
original GGA correlation in revPBE, "pbc" here, is used? As 4.3.1 allow user
to specify GGA correlation and vdW correction simultaneously, and vdW-DF in
that version is 1/4/4/0/1, is it reasonable to add GGA correlation in the
functional and perform further calculation? I note in literature it is said
GGA correlation is small so it is neglected.

2.       What is the difference of vdW functional correction in vdW-DF1 and
vdW-DF2?

3.       If it is impossible to get a pseudo-potential of vdW-DF , what
functional in pseudo-potential should I specify to perform calculation
later? What is the pp generated by 4.3 actually and can they be used in
further calculation?

 

Thanks.

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