[DFTB-Plus-User] Bug fix of dispersion correction for periodic systems in release 1.2

[Christoph Lechner]

Hi!

In the changelog of version 1.2 you mentioned a bug fix of the
dispersion correction for periodic systems.
Since one of my students calculated a periodic system containing a
carbon nanotube with version 1.1 I have some questions regarding this
change.

Did this affect both dispersion models? We have used the Slater-Kirkwood
model for our calculations.

Did this affect both the gradient and singlepoint calculations?
I ask this because I redid some calculations, geometries obtained with
version 1.1 yielded the same singlepoint energy with version 1.2. I also
redid some geometry optimizations and overall the optimized system had a
lower energy starting from the same input geometry.

Do you have any experience, what the overall error of the dispersion
correction is with version 1.1, since I have to decide if these
calculations should be redone with the new version.

Best regards,
Christoph Lechner