[DFTB-Plus-User] slater koster files

[Roozbeh Anvari]

Dear DFTB users,

I need a simple non SCC description of the bands of graphene for a
transport code I am writing,

please see the attached H0 profile for C-C interaction I am extracting from
mio set ( that of pbc set looks exactly the same)

[image: extracted_H0.jpg]
please compare the above results with the following
Porezag, D., Frauenheim, T., Köhler, T., Seifert, G., & Kaschner, R. (1995).
Construction of tight-binding-like potentials on the basis of
density-functional theory: Application to carbon. Physical Review B, 51(19),
12947.   Cited by 1966

it can be seen that the H0 values are a bit different to the standard TB
(DFTB0) values, I was wondering if the curves should not be exactly the
same to those of
conventional TB parameters ?  because at least in the case of graphene that
I am currently studying the structure is symmetric and induced charges in
the SCC-DFTB should be zero,

the gridDist parameter in the .SKF file is .02, however if I shift the
profiles by 0.3 Bohr  to the right (initial interatomic distance of 0.32)
then I get the exact band structure.

would you please advise if I am not extracting the correct profile from
.SKF file, or else I need to perform the iterative SCC-DFTB to get the
correct results ?

Best
Roozbeh












On Thu, Jan 9, 2020 at 12:58 PM Roozbeh Anvari <roozbeh.anvari at gmail.com>
wrote:

>
> Dear community
>
> I have a question about interpreting .SKF files,
>
> H_ppπ  for C-C interaction at an interatomic distance of 1.42 angstrom
> should be ~ 3eV, (for example see Porezag, D., Frauenheim, T., Köhler,
> T., Seifert, G., & Kaschner, R. (1995). Construction of
> tight-binding-like potentials on the basis of density-functional theory: Application
> to carbon. Physical Review B, 51(19), 12947. )
>
> while by interpolating to parameterized  H0 in mio and pbc sets I get a
> value of -2.03 eV,
>
> Thank you in advance
> Roozbeh
>
>
>
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