[Pw_forum] About NON COLLINEAR magnetism
xhongjun at mail.ustc.edu.cn
Wed Oct 20 16:50:23 CEST 2004
Stefano Baroni wrote:
> Dear Xianghjun:
> the present version of PWscf cannot deal with spin spirals. An old
> version of it actually did. You may want to get in touch with Ralph
> Gebauer (rgebauer at ictp.trieste.it) for more details on the actual
> availability of that old version. Even better, you may want to
> volunteer and patch the routines for spirals contained in that old
> version into the new one ;-) Some details that you may find
> interesting (along with some nice ideas on magnon dynamics,
> constrained DFT, etc.) are contained in Ralph's PhD thesis, available
> on the web at URL www.cecam.fr
> Concerning J, the best way to calculate it is by constrained DFT. What
> ought to be done is to calculate the energy difference between
> configurations in which the magnetic moments on neighboring atoms are
> constrained to different directions, and then fit the results to kind
> of a Heisenberg model. Again, constrained DFT used to be implemented
> in PWscf in the past, using the penalty function technique that is
> described e.g. in Ralph's thesis. If it is no longer implemented, it
> would be very easy to re-implement it.
> Hope this helps
> Yours, Stefano B
> On Oct 20, 2004, at 10:04 AM, xianghjun wrote:
>> xianghjun wrote:
>>> Dear all:
>>> I want to deal with the non-collinear magnetism systems using
>>> would you please recommend some references about the implementation
>>> in PWNC?
>>> P.S., I want to get the exchange parameter J using PWNC, is that
>>> Best regards,
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>> An other related question is:
>> Can PWNC deal with spin spirals?
>> I have examined the input help file "INPUT_NC",
>> it seems that the answer is "no".
>> Am I right?
>> Best regards,
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
> Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
> via Beirut 2-4 34014 Trieste Grignano /
[+39] 040 3787 406 (tel) -528
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Thank Baroni and Ralph for helpful comments.
I have downloaded Ralph's PhD thesis and have found that the thesis is
interesting. If I could and if the developers have no such plans, I will
be very happy to patch
the routines for spirals into the new PWSCF version.
Fortunately, I find that there are some input parameters to constrain
the magnetic direction
in the INPUT_NC file. So the constrained DFT should be implemented in
the present PWSCF version.
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