[Pw_forum] magnetization

[Evren Ataman]

Dear Sena

Here is a nonexpert comment on your email.
The starting_magnetization(3)= 0.5 line in your input file tells Quantum
Espresso that the THIRD entry in the ATOMIC_SPECIES has a starting
magnetization of 0.5. In your case it happens to be Mn. During the
optimization process this value will also be optimized.
Answer to your third question is yes. During the optimization process in
the output file you will see that spin up and down calculations are
performed separately.
There is one more keyword you can use, that is, tot_magnetization. This
keyword sets a magnetization to your super cell and the value is kept
constant during optimization process. In this way one forces the system to
be magnetic with certain value.

There are a lot of discussion in the forum on this topic, I recommend you
to use
http://www.mail-archive.com/pw_forum@pwscf.org/
and search for "magnetization", "spin polarization" etc.

Evren Ataman


On 5 April 2015 at 23:41, <senaguler at trakya.edu.tr> wrote:

> Dear users
> I am trying to calculate electronic band structure and DOS of Mn doped BN
> nanowires.
> I know that transition metals are ferromagnetic materials in the
> semiconductor systems.
> I've prepared input file for this system but I don't sure that chosen
> magnetization parameters
> are correct and I have a few questions.
> Q1. How many "starting magnetization parameters" should be in input?
> Q2. Should I do starting magnetization(3)? (because there are 3 different
> types of atom).
> Q3. Finally, is this calculation do both of spin up and spin down states?
> Thanks.
> Sena Guler Ozkapi
> PhD Student
> Department of Physics, Trakya University, Turkey.
>
> I've included my input.
>
>   &control
>     calculation='relax'
>     restart_mode='from_scratch'
>     pseudo_dir='/usr/pseudo'
>     outdir='./tmptest'
>     prefix='nw',
>  /
>  &system
>    ibrav           = 0,
>    celldm(1)       = 6.8,
>    nat             = 37,
>    ntyp            = 3,
>    ecutwfc         = 40,
>    ecutrho         = 400,
>    occupations     = 'smearing',
>    smearing        = 'mv',
>    degauss         = 0.02,
>    nspin           = 2,
>    starting_magnetization(3)= 0.5,
> /
>  &electrons
>  /
>  &ions
>    upscale=10,
>  /
>
> ATOMIC_SPECIES
> B  1.0 B.pbe-n-van_ak.UPF
> N  1.0 N.pbe-van_ak.UPF
> Mn 1.0 Mn.pbe-sp-van.UPF
>
> ATOMIC_POSITIONS {alat}
> B -1.000000 -0.500000 -0.500000
> N -0.750000 -0.250000 -0.250000
> N -0.750000 -0.750000 0.250000
> B -1.000000 0.500000 -0.500000
> B -1.000000 0.000000 0.000000
> N -0.750000 0.750000 -0.250000
> N -0.750000 0.250000 0.250000
> B -0.500000 -1.000000 -0.500000
> B 0.000000 -0.500000 -0.500000
> B 0.000000 -1.000000 0.000000
> B -0.500000 -0.500000 0.000000
> N -0.250000 -0.750000 -0.250000
> N 0.250000 -0.250000 -0.250000
> N 0.250000 -0.750000 0.250000
> N -0.250000 -0.250000 0.250000
> B -0.500000 0.000000 -0.500000
> B 0.000000 0.500000 -0.500000
> Mn 0.000000 0.000000 0.000000
> B -0.500000 0.500000 0.000000
> N -0.250000 0.250000 -0.250000
> N 0.250000 0.750000 -0.250000
> N 0.250000 0.250000 0.250000
> N -0.250000 0.750000 0.250000
> B -0.500000 1.000000 -0.500000
> B 0.000000 1.000000 0.000000
> B 0.500000 -1.000000 -0.500000
> B 1.000000 -0.500000 -0.500000
> B 0.500000 -0.500000 0.000000
> N 0.750000 -0.750000 -0.250000
> N 0.750000 -0.250000 0.250000
> B 0.500000 0.000000 -0.500000
> B 1.000000 0.500000 -0.500000
> B 1.000000 0.000000 0.000000
> B 0.500000 0.500000 0.000000
> N 0.750000 0.250000 -0.250000
> N 0.750000 0.750000 0.250000
> B 0.500000 1.000000 -0.500000
>
> K_POINTS {automatic}
>  1 1 8 0 0 0
>
> CELL_PARAMETERS { cubic }
> 5.0    0.0                  0.0
> 2.5    4.330127019   0.0
> 0.0    0.0                  1.0
>
>
>
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20150406/adf3dc81/attachment.html>