[DFTB-Plus-User] About point charges

[Ben Hourahine]

Hei Markus,

1) the energy for the DFTB system in the field of the charges is included
2) The point charges are periodic if the system is periodic (usual Ewald
summation method)
3) These are not printed, but can be evaluated internally. We can add
this as a feature for the next release, but they are accessible from the
interface to the addForceDCSCC routine. It is just that at the moment
the main dftb+.F90 call does not supply the the optional array that
holds them.

The situation for stress tensor calculations is less developed, so
external charge contributions are not currently available, even internally.

Regards

Ben

On 04/09/16 07:10, Markus Kaukonen wrote:
> Dear all,
> All questions about external point charges
> 1) Does the total energy include the coulomb energy between the
> dftb-system and point charges.
> 2) Are the point charges periodic if the dftb-system is periodic
> 3) Is it possible to get the forces caused by the dftb-system on the
> point charges?
> Terveisin Markus

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