Hi Raha,
It can be slightly difficult to compare between methods. Are you
ensuring that the basis set size is the same between DFTB and DFT
methods for example?
I can suggest either tightening convergence criteria or else increasing
number of k points. (In the paper linked they used a 4x4 k point grid
whereas you use gamma point). Averaging over multiple k points would
help to smear out the spikes.
Regards,
Aaron
On 22/05/16 13:41, Raha khalili wrote:
Dear Nick and Aaron,
Many thanks for your reply. Yes, my calculations has converged as you
can see in my attached output files.
On Sun, May 22, 2016 at 1:34 AM, Thong, Aaron
<[email protected] <mailto:[email protected]>> wrote:
Hi Raha,
How do you define what is correct for your transmission? Are you
trying to reproduce a certain literature result?
I am trying to do some calculations on amine-linked single molecular
junctions with DFTB and I need to compare my results to DFT (the
results from DFTB are attached). My DFTB transmission is smoother than
DFT one and I can not compare these two calculations. There also is a
DFT calculation on a same structure in "PHYSICAL REVIEW B 83, 115108
(2011)" that differs from my calculations.
I'm not sure if my Transiesta calculations is correct or not. As
first, I optimized the attached molecule to electrodes by siesta, then
used the optimized structure in my Transiesta calculation.
Regards,
Raha
Spike peaks in transmission is quite common for single molecule
junctions since the Dos of these junctions would be spikes.
Regards
Aaron
Sent from my Samsung device
-------- Original message --------
From: Raha khalili <[email protected]
<mailto:[email protected]>>
Date: 21/05/2016 9:35 pm (GMT+00:00)
To: [email protected] <mailto:[email protected]>
Subject: [SIESTA-L] Transmission problem
Dear All,
I am trying to find the transmission of a single molecule junction
by using Transiesta but the final result doesn't seem to be
correct with many spike-like peaks.
Here are attached my input files and final T results.
Any help will be really appreciated.
kind regards,
Raha
--
Khadijeh Khalili
Nanotechnology group, Physics department, university of Mazandaran
Babolsar, Iran
--
Khadijeh Khalili
Nanotechnology group, Physics department, university of Mazandaran
Babolsar, Iran
--
PhD student
B321/28
Aaron Thong
