[Pw_forum] fixed spin moment calculations

[Paolo Giannozzi]

On Apr 4, 2007, at 23:14 , Eyvaz Isaev wrote:

>> I will like to do fixed spin moment calculations, .i.e. I want the
>> magnetization (such as 5.0 uB) to be kept fixed in my calculations.
>> Can anyone kindly suggest me the parameter(s) or how to specify the
>> options in the manual?

>> From INPUT_PW
>
> fixed_magnetization(3)  REAL (default 0.d0)
>                value of the total magnetization to be maintained  
> fixed when
>                constrained_magnetization='total'

there are actually (2N+1) different ways to fix the magnetization.
The one mentioned above is good for calculations with noncollinear
magnetism. For LSDA calculations, the relevant variable is
"total_magnetization", or alternatively "multiplicity" (also "nelup/ 
neldw",
not recommanded). Documentation (sort of) in INPUT_PW

Paolo
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Paolo Giannozzi, Democritos and University of Udine, Italy