[Pw_forum] magnetic field

[Mems Aghaee]

Hi

I am a PhD student and i have begun quantum-espresso soft ,recently.

I saw this formula in Input data description for constrained_magnetization:

LAMBDA * SUM_{i} ( magnetization(i) - fixed_magnetization(i))**2

I don’t understand how to be used this formula in quantumespresso.

For example I took 0.2 Ry for magnetic field in my output. but I don’t know how to transfer Ry toTesla?

I used this formula: U =  μ. B      (formula 1)

Is this correct?

Actually Iknow Total magnetization without applying magnetic field is 2.67 magneton bohrafor Fe and I know Fe can have Total magnetization =4 , totally.

Then i want to achieveTotal magnetization = 4  when I applyMagnetic field.

So for this work idid 4 – 2.67= 1.33 magneton bohra and I put fixed_magnetization(3) = 1.33magneton bohra and I took -0.03 Ry for magnetic field in my output.

I transfered 0.03 Ryto joule and I achieved  0.6  10^-19 joule and I transfer 1.33 magnetonbohra to joule/Tesla and I achieved 12.3  10^-24 joule/Tesla.

Then I used thisformula: U = μ . B and I achievedB = 5000 Tesla , approximately  and Ithink this amount is unreasonable.

And if I use thisformula: u= B^2/2 μ . (formula2)

I wont havepermibility for different kinds of nano particles for example Fe3o4 that I amworking on it.


 
And my last questionis: i did my calculation Collinear, is this correct? Or I should do my calculationnoncollinear?


Please guide me.My phone number:00989125535899

My email: mems_aghaee at yahoo.com 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20161121/f9570d98/attachment.html>