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. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110824/e6c3ec4b/attachment.htm