Dear PWSCF developers. I want to evaluate the force from vdW interaction and
compare the DFT-D and vdW functional implemented in PWSCF. Then, I saw the source code of mm_dispersion.f90, the implementation of DFT-D. I found in force_london in mm_dispersion Modules, a condition IF (ata /= atb) THEN .... ENDIF But, if ata ==atb ( same atom in the system), there must be a contribution of vdW force from the periodic images of the same atom (index =ata=atb) within the cutoff radius of vdW, I think the condition (if ata/=atb) drops such a contribution. And in CVS version of PWSCF implementation of vdW functional in vDW_DF Modules, it seems there is a stress calculation function, but still no force calculation function within non-local vdW functional. Are there plan to implement the force from vdW interaction within SCF scheme. Sincerely. Yukihiro Okuno.