[Pw_forum] Band structure of non-metallic antiferromagnet

[Silvia Bahmann]

Hi,

of course, I read the input documentation and tried without tot_magnetization.
(    nspin = 2,
     starting_magnetization(1) = 1,
     starting_magnetization(2) = -1)

But when starting pw.x the following error message appeared:

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from iosys : error #         1
      fixed occupations and lsda need tot_magnetization
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

This caused me to use tot_magnetization.

Any suggestions?

Silvia Bahmann

Institute for Theoretical Physics
TU Bergakademie Freiberg
Germany


> From: Paolo Giannozzi <giannozz at democritos.it>
>
> On Dec 17, 2010, at 15:06 , Silvia Bahmann wrote:
>
>> In v. 4.2.1 of QE one has to define antiferromagnetism in
>> an insulator like this:
>>
>>    starting_magnetization(1) = 1,
>>    starting_magnetization(2) = -1,
>>    tot_magnetization = 0
>
> actually the input documentation says
>                  If you fix the magnetization with "tot_magnetization",
>                  you should not specify starting_magnetization.
> Setting starting_magnetization should be sufficient to produce an AFM
> state (if the systems wants to go there)
>
>> Is there another way to define the antiferromagnetism since nelup and
>> neldw are not available anymore?
>
> tot_magnetization does exactly the same as nelup, neldw. Too many
> ways to specify the same thing are a source of confusion.
>
>> And why is the bands code not working?
>
> maybe it is just an overzealous check (always preferrable to
> insufficient
> checks allowing to produce meaningless results). You may try to locate
> the error message and to disable it if you think that there is  no
> good reason
>
> P.
> ---
> Paolo Giannozzi, Dept of Chemistry&Physics, Univ. Udine
> via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222