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The definition for initial spin direction
Date: 2020/04/23 15:54
Name: Chong Wang   <ch-wang@outlook.com>

Hi,

I am wondering what is the definition for initial spin direction.

The manual reads:
8: Euler angle, theta, of the magnetic field for spin magnetic moment
9: Euler angle, phi, of the magnetic field for spin magnetic moment
Also, the 8th and 9th are used to generate the initial non-collinear
spin charge distribution

However, the spin direction and spin magnetic moment is opposite. Therefore, will the following line:
1 Fe 0.0 0.0 0.0 8.0 6.0 0.0 0.0 0.0 0.0 0 off
initialize 2 spin-up electrons in the +z or the -z direction?


Thank you,

Chong
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Re: The definition for initial spin direction ( No.1 )
Date: 2020/04/23 17:09
Name: Naoya Yamaguchi

Hi,

In that case, the initial spin polarization is 2 muB. And, if +z or -z is meaningless unless you consider spin-orbit interaction.
You may refer to the following:
http://www.openmx-square.org/forum/patio.cgi?mode=view&no=2618

Regards,
Naoya Yamaguchi
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Re: The definition for initial spin direction ( No.2 )
Date: 2020/04/24 03:36
Name: Chong Wang  <ch-wang@outlook.com>

Thank you.

I have included the spin-orbit interaction and I want to make sure of the magnetization direction of the calculation, which is opposite of the spin direction. This matters, for example, when calculating anomalous Hall effect. The anomalous Hall conductivity changes sign if the direction of magnetization is flipped.

So the question is: is the direction in the input file set for spin moment or spin?

Chong
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Re: The definition for initial spin direction ( No.3 )
Date: 2020/04/24 06:41
Name: Naoya Yamaguchi

Dear Chong,

>So the question is: is the direction in the input file set for spin moment or spin?
The eighth and ninth column values correspond the magnetic field that is easy to be parallel to the direction of the spin moment and antiparallel to that of the spin.

Regards,
Naoya Yamaguchi
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Re: The definition for initial spin direction ( No.4 )
Date: 2020/04/24 13:12
Name: Chi-Cheng Lee  <cclee.physics@gmail.com>

Dear Chong,

They should be spin "angular momentum". I think when OpenMX calculate magnetic moment,
"-e" has been multiplied later on. But this needs to be confirmed by Professor Ozaki.

Regards,
Chi-Cheng


メンテ
Re: The definition for initial spin direction ( No.5 )
Date: 2020/04/24 13:37
Name: Chong Wang  <ch-wang@outlook.com>

Dear Chi-Cheng,

Thank you for the information. My anomalous Hall calculations are more consistent with 8-9th columns being direction of spin angular momentum instead of spin magnetic moment.

Chong
メンテ

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