Dear all, I would be really grateful if you clarify a little more about the inclusion of vdW interactions in siesta calculations. I have read the Alberto Garcia's note in the following link.
https://www.mail-archive.com/siesta-l%40uam.es/msg08564.html He says, "Instead, we recommend to generate the pseudopotentials with a good GGA functional like PBE, optionally changing the exchange part by that of the vdW functional to be used. This note will be added to the Siesta documentation as soon as possible." *Does he mean the inclusion of the following lines in the .fdf file and using the GGA-PBE pseudopotentials?* *%block XC.hybrid2GGA PBE 0 1VDW DRSLL 1 0%endblock XC.hybrid* Or should I set the following lines in the main .fdf file instead and use the GGA-PBE pseudopotentials? XC.Functional VDW XC.authors DRSLL If I use the latter strategy, I think the following warning in the output file is always inevitable: xc_check: Exchange-correlation functional: xc_check: VDW Dion-Rydberg-Schroeder-Langreth-Lundqvist xc_check: WARNING: Pseudopotential generated with GGA PBE functional Please guide me on this issue. Should I ignore this warning? Bests, Mohammad,
