QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: ocdor on July 5, 2017, 10:16

Title: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 5, 2017, 10:16

Dear ATK experts,
              I have calculated the EDP(enclosed in attachment). Right and left electrode is 0V,but materials is not in accordence. The work function difference of two electrode materials is 1.1eV. Is my result right?   

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Ulrik G. Vej-Hansen on July 5, 2017, 10:19

Please provide more information about the system, preferably also the python script you have used and any log-file from the calculation.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 5, 2017, 11:17

Thank you ! The model and log are enclosed in attachment.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Ulrik G. Vej-Hansen on July 5, 2017, 13:50

Thank you, but please provide the log-file from the actual calculation, not just the EDP analysis. I apologize that was not clear. Please also provide the python script(s) you have used.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 5, 2017, 14:47

sorry, the total log film is too large to post.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Petr Khomyakov on July 5, 2017, 17:24

Quote from: ocdor on July  5, 2017, 10:16

Dear ATK experts,
              I have calculated the EDP(enclosed in attachment). Right and left electrode is 0V,but materials is not in accordence. The work function difference of two electrode materials is 1.1eV. Is my result right?

The difference of the EDP values in the left and right electrodes does not need to be zero if the bias voltage is zero, unless the electrodes are identical and the system has a mirror symmetry, but this is not the case. So, I guess the result is correct.

I would, however, increase the central region of your device, as the electrode extensions now seems to be directly coupled to the overlap region where the actual scattering takes place.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 6, 2017, 03:46

Thank you for your careful reply. What's the difference between average and through point?

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Petr Khomyakov on July 6, 2017, 08:23

Take a look at the section on "Electron charge density projections" in this tutorial http://docs.quantumwise.com/tutorials/espresso_gui/espresso_gui.html.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 6, 2017, 09:25

Thank you! My Y-axis is  δVE(r) but others are  δVH(r). What's wrong with my calculation or related to my calculation setup?

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Petr Khomyakov on July 6, 2017, 19:26

What version of ATK are you using? In ATK2016, we had changed definition of the Electrostatic and Hartree Potentials as well as the related Differences. New Hartree potential is (-1) Old Electrostatic potential, and  New Electrostatic potential is (-1) Old Hartree potential. The units of the New Hartree  potential and New Electrostatic potential are eV and Volt, respectively.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: ocdor on July 7, 2017, 02:53

Thanks, my ATK version is 2016.

Title: Re: Can Work funtion difference between right and left reflect in EDP?
Post by: Petr Khomyakov on July 7, 2017, 09:55

If ATK-2016, then your potentials are defined in new convention that we  will keep for all the future releases, including the newest ATK-2017.0  that is already available for download on our website.