[Pw_forum] Restart calculation of LSDA

Gabriele Sclauzero sclauzer at sissa.it
Mon Mar 2 15:31:17 CET 2009


hanghui chen wrote:
>       However if I run a spin-polarized calculation (LSDA), I find 
> that a system could be paramagnetic at "high temperature" and 
> ferromagnetic at 'low temperature'. 

That's plausible, since the magnetization is more hard to converge wrt to smearing than 
the total energy. The former is much more sensitive to the details of the band structure 
around the Fermi energy (and hence on the value used for the BROADENING parameter) than 
the latter.

If you're sure that the ground state of your relaxed system will be ferro, why don't you 
try to constrain the total magnetization (search for constrained_magnetization in 
Doc/INPUT_PW.txt) and then relax the constrain at the end (though not sure that this last 
step can be done actually...).

Another, more simple, solution would be to start from_scratch the "small temperature" run 
using the atomic positions from the previous run at "high temperature".

GS

>  
> Hanghui Chen
> Department of Physics
> Yale University
> 
> 
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