[DFTB-Plus-User] R: Help with DFTB+

[Alessandro Pecchia]

Dear Morgan,

 

indeed the block kPointsAndWeights is missing. 

You did not attach the gen file, coords.gen, but for sure this is defined as a periodic system (Supercell) and this requires kpoints.

 

The block is not needed only if you are computing transport for a cluster geometry, that might be represented by a nanowire,  

a nanojunction or for instance a nano-ribbon, i.e., whatever that is non-periodic in the direction transversal to transport.

(The periodicity along the transport direction is disregarded anyway)

 

So probably the solution to your problem is to change in coords.gen  ‘S’ for ‘C’. 

Again this makes sense *only* if your structure is intended non-periodic in the transverse direction(s).

 

On the other hand, if you have defined a dummy periodicity for whatever reason (i.e., vacuum spacers) then simply add the block:

 

KpointsAndWeights = SupercellFolding{

1 0 0

0 1 0

0 0 1

0.0 0.0 0.0

}

 

In case of doubts send me the structure and I can check if it makes sense.

 

Regards,

 

Alessandro Pecchia

 

 

Da: DFTB-Plus-User [mailto:dftb-plus-user-bounces at mailman.zfn.uni-bremen.de] Per conto di Morgan Jackson
Inviato: mercoledì 15 novembre 2017 21:54
A: dftb-plus-user at mailman.zfn.uni-bremen.de
Oggetto: [DFTB-Plus-User] Help with DFTB+

 

Hi,

 

When I run my device file, I get the error "Error! Missing Child: KPointsandWeights". What am I doing wrong? Here's the device and source/drain files I've been using.

 

-Morgan Jackson

Yale '18

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