QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: ph on August 7, 2012, 15:24

Title: Calculator settings for transport properties of 2d Graphene and 1D nanoribbon
Post by: ph on August 7, 2012, 15:24

Dear Sir,
Can I use (similar pattern) calculator settings for 2D graphene transport  (Electrode 1x1x50  and  central region 1x1x50 ) and 1D graphene nanoribbon(  Electrode 1x1x50  and  central region 1x1x50) like this? or  for 2D transport is there any other pattern needed?. Or this is depends on any other issues?.

Kind regards

Title: Re: Calculator settings for transport properties of 2d Graphene and 1D nanoribbon
Post by: mads.engelund on August 9, 2012, 09:58

No, the correct pattern for graphene transport is (1x Ny x Nz), assuming that y is the periodic direction.

K-points are used when a direction is periodic (and also in the transport direction). Exactly how big Ny should be depends on how delicate a property you are trying to model. But think that at least Ly/Ny > 25 Angstrom, where Ly is the size in the y-direction. This may not be enough, however, think of it as a convergence parameter.

Also, for graphene transport, use an odd number for Ny, since for some transport directions, this will make sure that the Dirac point is included in the calculation. This will improve the results.

Title: Re: Calculator settings for transport properties of 2d Graphene and 1D nanoribbon
Post by: ph on August 9, 2012, 11:13

Dear Sir, Thanks  for your reply.
 
Is it Ly/Ny >25 Angstrom a ratio ?   or  Ly or Ny>25 ?. Kindly give me some more clarity.

Kind Regards