[Pw_forum] [Fwd: paramagnetic structure]

[Davide Ceresoli]

Subhradip Ghosh wrote:
> Dear Davide,
> 
> All I wanted to know is the following thing: How does espresso capture the
> randomness in local moments in paramagnetic phase?

Ah, that's a different story! that's the right question!

All calculations are zero temperature and they are like a snapshot of the
system, with all spin frozen.

At any finite T there will be spin excitation (magnons). In the past
Baroni and Gebauer computed the magnon dispersion in a metal. The role
of temperature is to destroy the magnetic order (FM and AFM) and
above a transition temperature (T_Curie for FM and T_Neel for AFM) the
system will behave as a paramagnet.
This is not straightforward to do with a single ground state calculation.