TMR Negative percentage

[Aadhityan]

I am getting negative percentage for TMR  by using the sample script in your example section. What this mean? Does my system structure is wrong?

[Daniele Stradi]

Difficult to say without even seeing the system structure    It would be great if you can attach it.

[Daniele Stradi]

Did you read the TMR tutorial for Fe-MgO-Fe?

http://docs.quantumwise.com/tutorials/fe_mgo_fe/fe_mgo_fe.html

Do you manage to get the correct TMR for Fe-MgO-Fe as described in the tutorial?

What makes you think that you should get the same for Fe-MgO-Ni?

[Aadhityan]

Also some other TMR devices also I tried. Some of them giving positive percentage. But some structure gave negative percentage. I also checked optimization of the devices two three times.

[Anders Blom]

There is nothing inherently wrong with negative TMR, you can find many such results in the literature by a quick Google search. If it's correct or not, depends of course on how accurately the calculation was set up. But if you look at the definition of the TMR, nothing prevents it from being negative.