Thank you very much for your prompt answer. I checked my previous calculations using vdW-DF and found that the vdW_kernel_table was copied in the prefix.save folder, which didn't happen for rVV10 case.
So I did copy the rVV10_kernel_table there (same folder where the copied UPF file resides) but received the same error message. I was not sure if it is looking for the vdW_kernel_table (I don't think it should) so I also placed the vdW_kernel_table but the error message didn't change. In the $prefix.save folder, I have rVV10_kernel_table, vdW_kernel_table, charge_density.dat, data-file.xml, charge_density.old.dat, and many K00## folders. Is there something that I am not doing right? Thank you again for your help and suggestions. All the best, Jin Chang, University of Toronto
