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QuantumATK => General Questions and Answers => Topic started by: gayani2025 on July 9, 2025, 07:43

Title: Problem in attaching the electrodes after device central optimization
Post by: gayani2025 on July 9, 2025, 07:43

Dear All,
I am currently following the tutorial at:
https://docs.quantumatk.com/tutorials/fe_mgo_fe/fe_mgo_fe.html#femgofe-started
As instructed, I have separated the device central region. However, I am now trying to attach the left and right electrodes using the "Device from Bulk" tool, but it doesn't seem to work.
Could you please advise me on how to proceed or let me know what I might be missing?
Thank you for your help.
Best regards,

Title: Re: Problem in attaching the electrodes after device central optimization
Post by: AsifShah on July 11, 2025, 13:46

Hi did you keep any layer fixed during optimistic?

Title: Re: Problem in attaching the electrodes after device central optimization
Post by: gayani2025 on July 11, 2025, 14:26

Hi Asif,

Thank you for the message. I kept all three layers of Ni and Au fixed. Only allowed one layer closer to molecule relaxed.  In the tutorial it says ....

"Next, open the optimization_icon Optimization block to specify that the first and last four atoms in the central region (the atoms in the electrode extensions) should be kept fixed during the relaxation. This is very important – if any of these atoms move you no longer have a periodic structure at the edges of the central cell, which is required for generating and attaching device electrodes later on."