[DFTB-Plus-User] R: A question on transport

[Alessandro Pecchia]

Hi,

In principles it is correct. 
Just be sure the header of P-P.skf is right  (a reasonable Hubbard parameter, number of electrons etc).
You could take P-P.skf from the "mio" set. 

You have to add a dummy Spline to the end of the files Si-P, P-Si. Copy-paste from any other.

Perhaps an important point is if you are tuning the correct position of the doping level within the gap. From dft/dftb calculations I guess it does not come to the right place but I never checked this. 

Regards,

Alex


-----Messaggio originale-----
Da: DFTB-Plus-User [mailto:dftb-plus-user-bounces at mailman.zfn.uni-bremen.de] Per conto di Gabriele Penazzi
Inviato: martedì 1 maggio 2018 20:15
A: dftb-plus-user at mailman.zfn.uni-bremen.de
Oggetto: Re: [DFTB-Plus-User] A question on transport

On 05/01/2018 06:58 PM, ZHAOHUI HUANG wrote:
> Hello,
>
>      Sorry to bother you. I am going to calculate I-V output curve with MPI-NEGF codes embedded in DFTB+. The system is phosphorous doped Silicon nanostructure. Since there is no P-related S-K file, I have included several characteristic P contained structures and fitted Si-P TB parameters out of their band structure. Because large value of bohr radius of doping electron, I include third order nearest neighbor to represent long range interaction. Now my question is, I assume that NEGF calculation is static run, and no need to create full set of TB parameters, that is, no need to figure out the influence of two-body repulsion (because I don't relax the structure). If so, I plan to create S-K file whose format is compliant with those used by DFTB+ code, simply copy my version of TB parameter as many times as grid points (No repulsion representation). Please comment whether or not this handling is acceptable? thanks a lot.

Hi,

it's correct, you don't need the repulsive potential for transport calculations.

Gabriele


_______________________________________________
DFTB-Plus-User mailing list
DFTB-Plus-User at mailman.zfn.uni-bremen.de
https://mailman.zfn.uni-bremen.de/cgi-bin/mailman/listinfo/dftb-plus-user