QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: guyue03 on November 15, 2018, 13:10

Title: SCF can't be converged when calculating zero-bias transmission in MTJ device
Post by: guyue03 on November 15, 2018, 13:10

Hi,
  Here is my problem. The  SCF can't be converged when calculating zero-bias transmission in MTJ device by using ATK 17. However, SCF is finished when using ATK 13.
  Could you tell me how to solve this problem? I want to do the calculation with ATK 17. The file is attached.

Thank you so much！

Title: Re: SCF can't be converged when calculating zero-bias transmission in MTJ device
Post by: Petr Khomyakov on November 15, 2018, 14:48

Take a look at NEGF convergence guide at https://docs.quantumwise.com/technicalnotes/negf_convergence_guide/negf_convergence_guide.html.

You may also try increasing the electrode extensions and reduce damping factor. Another thing is to change Equivalent Bulk, https://docs.quantumwise.com/manual/Types/EquivalentBulk/EquivalentBulk.html, to Neutral Atom, or vice versa to see if that changes the convergence behavior.

It would also be helpful to see your log files for the calculations done with 2013 and 2017 versions. Did you use the same python script for the two calculations.

Title: Re: SCF can't be converged when calculating zero-bias transmission in MTJ device
Post by: guyue03 on December 3, 2018, 06:51

Thank you so much!