How can we perform Non-equilibrium Green's function based calculations? please recommend some simulation package for Non-equilibrium Green's function based calculations with its procedure.
Is it possible to perform Non-equilibrium Green's function based calculations by vasp?
Til my knowledge, TranSIESTA and ATK do what you want.
GAMESS-US, GAUSSIAN, ABINIT and Quantum Espresso, don't.
You're also welcome to try out NEGF in ADF and DFTB in the ADF Modeling Suite.
SIESTA use it in the TRANSIESTA module to calculate transport properties (http://departments.icmab.es/leem/siesta/).
Also, the Atomistix ToolKit (ATK) (http://quantumwise.com/).
Mr. Askari,
This formalism, i.e. non-equilibrium Green's one is a module of Gaussian (www.gaussian.com). It is not free of charge. There is available in Gamess-US as well (http://www.msg.ameslab.gov/gamess/). The last program-package is free of charge.
The code you want to use will depend on several factors: What do you want to do, accuracy you want to achieve, the type of system you're studying, and so on. So it would be good if you provided a more detailed description of your goals.
So long I have worked with SIESTA (TranSIESTA) and GPAW (or even de ASE transport module), both of which are free and open source, so the code will even help you undestand the formalism. I do know there are several other packages that can help you do transport calculations (Quantum Espresso, Abinit, NEMO-5, GAMESS, etc.), So a specific answer to your question depends on what you intend to do.
I wanna calculate transport properties of 2D materials and other related properties for device applications.
Til my knowledge, TranSIESTA and ATK do what you want.
GAMESS-US, GAUSSIAN, ABINIT and Quantum Espresso, don't.
You should also try GPAW. Its python interface makes it pretty easy to use and for 2D structures (if the size of the system stays within 10^2 atoms) works ok.
Hi!
I suggest you, at first you see the below book:
S.Datta, Quantum transport: atom to transistor, Cambridge, 2005
and repeat its examples .
For doing NEGF, you should, not only , solve the Schrodinger equation but also Poisson equation simultaneously, because, by applying the bias voltage the charge has not equilibrium distribution.
But in practice, any one assumes that, the transmission is only a function of electron energy i.e.,T=T(E) and conductivity is equal to: Integral ( f(E) T(E) dE) where f(E) is Dirac distribution function. Of course E is near to Ef, where Ef is Fermi energy.
You can download Trans- SIESTA package (free of charge) and run NEGF for your problem.
Best Regards
Hi,
Which are the key parameters in the localized basis sets in determining the accurate transmission spectra and IV-curves? For example, we use hybrid functionals for the prediction of accurate band gap or increase the k-mesh to calculate DOS, what about in the case of transmission spectra and IV- calculations by localized basis sets? Right now I am using transiesta for NEGF calculations and found some inconsistencies with ATK calculations.
Looking for your comments, please.
Thank you.
Could we calculate transistor properties by transiesta? or by some other code than ATK? I would prefer freely available code.
Sure. If you want to calculate the transport properties of the channel, you can calculate transistor properties by setting a gate bias. I think codes that include these functionalities are Transiesta, GPAW, nanoTCAD, Quantum espresso...
Just check them out!
Thank you for your comment, in fact i am trying to calculate transistor properties by using transiesta but don't know how to set gate bias, the most important parameter.
You can write your own code. This site helps you:
http://www.itap.uni-kiel.de/theo-physik/bonitz/kbet2/kbet2_courses.html
I have tried to write a solution of time dependent Kadanoff Baym equations based on slave boson technique. I found an article that is attached on this message. But I need help to configure borders of numeric integrations of equation number A.9. Could anyone help me, please?
sorry this is outside the scope of transport planning and operations which i am working on.
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