Optimization of device central region

[Gaurav]

Dear all,

I have a query related to relaxing the device central region as mentioned in the following tutorial:
 https://docs.quantumatk.com/tutorials/fe_mgo_fe/fe_mgo_fe.html#femgofe-relax 

How can be we perform  optimization of similar system (mainly 2-probe model for PC/APC spin transport) if we have modified the left/right electode via substitutional doping or adsorbtion to induce magnetism?? As implying constraint type to rigid/fixed to electrode extensions will prevent necessary changes at substitution or adsorption site.

Thank you in advance.

[mlee]

Electrode extension is fixed during the optimization in the central region.
https://docs.quantumatk.com/manual/Types/DeviceConfiguration/DeviceConfiguration.html

If you need to modify one in the electrode extension, you should also repeat the electrode using the modified electrode extension. If you keep the original electrode, you need to modify one in central region not in the electrode extension.

[Gaurav]

Thank You Dr. Mlee.

[sumitn60]

Dear All,

I was trying to make a molecular junction in which the central region only consists of organic molecules, not the layers of metallic electrodes. However, as in ATK, the central region has to be the same or greater than the total size (left+right) of the electrodes; the central region always considers some layers of the electrodes. Is it possible to consider the only molecule as the central region to see the effects coming only from the molecule? However, electrodes may induce some effects on the molecule, but considering some metallic layers inside will definitely affect the results, what is your take on this?

Thanks
Sumit

[mlee]

The central region in the device model includes the electrode extension. Do you want to design the slab model?

[sumitn60]

But the extended molecules already consider the slabs from the electrodes... Is it possible to consider only the molecule as the central region and not the extended molecule (molecule+slabs of electrodes)?

[mlee]

Central region must have the electrode extension as same as the electrode bulk.