[Pw_forum] Finding Curie temperature

[German Samolyuk]

The simples way is to yse Heisenberg model. If you have system with well
localized magnetic moments, the bcc iron is one of them,
it will works pretty good.
You can calculate total energy of ferromangnetically (FM) ordered state and
anitferromagnetically (AFM) one.
Depending on type of AFM the difference of these two energies gives you
effective exchange parameter J_0.
in mean field approximation the Curie temperature T_c=2/3 J_0. Or more
complicate - you can map
set of exchange parameters to set of energies for differently magnetically
ordered states and obtain
T_C from this Heisenberg hamiltonian.
As I understand all other approaches wiil need modifications of the code.

Best,

German Samolyuk
Oak Ridge National Lab
USA

On Thu, Nov 18, 2010 at 8:26 AM, Padmaja Patnaik <
padmaja_patnaik at yahoo.co.uk> wrote:

> Hi
>
> How can we calculate Curie temperature using quantum espresso? If anybody
> can explain, it can be very helpful for me.
>
> Regards
> Padmaja Patnaik
> Research Scholar
> Dept of Physics
> IIT Bombay
> Mumbai, India
>
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