Internal dielectric constant in ALPB and GBSA

[choutkaj]

Hi all!

Thanks for all your work on xtb and the ALPB and GBSA solvation models. I am trying to figure out if there is a way to modify the value of the internal dielectric constant (dielectric constant of the solute) in these models within xtb. In the ALPB publication, this term is given as ϵin. For example, in amber this could be done by the "intdiel" variable, and it is common in the MM/GBSA world to tinker with the internal dielectric constant for a given system. It would be really useful to have this feature also in xtb.

I have found the GBSA parameter files, which contain the dielectric constant of solvent (ϵout), but not of solute (ϵin). Is there a way to set ϵin to a different value than the default 1?

Thanks!