[Pw_forum] hyperfine calculation

[Jones Tsz-Kai Wan]

Dear Gregor,

I'm just calculating HF tensor of an isolated Si atom, so I don't
think magnetic response matters. Below is summary of calculation.

QE version 4.1.1
Spin-polarization: 3 up and 1 down
Simulation cell: 10-angstrom cubic simulation cell
Ewfccut: 30 Ry
PP of Si:obtained at
http://www-int.impmc.upmc.fr/~software/gipaw/pseudopotentials.html

Besides Si atom, I also got zero dipole term for C, N, and O.

Regards,

Jones

On Wed, Dec 9, 2009 at 3:02 PM, Gregor Mali <gregor.mali at ki.si> wrote:
> Dear Jones Wan
>
>>
>> HF of Si:
>>
>>  Si   1: g_n = -1.110574                  MHz
>>  Si   1  hfi_dipole       0.000000       0.000000       0.000000
>>  Si   1  hfi_dipole       0.000000       0.000000       0.000000
>>  Si   1  hfi_dipole       0.000000       0.000000       0.000000
>>
>>  Si   1  hfi_dipole       0.000000       0.000000       0.000000
>>
>> Fermi contact term:        bare     reconstruction      total
>>                          0.000000      45.266354      45.266354
>>  **** ZORA ****
>>                          0.000000      42.470825      42.470825
>
> So far I've never obtained dipole coupling equal to zero! Are you sure
> that there are no mistakes in your spin-polarized scf calculation?
>
> (For example, the materials that I study are paramagnetic at room
> temperature, and antiferromagnetic at low temperature. However, if I
> want to obtain information on hyperfine coupling related to the
> paramagnetic state, I start with ferromagnetic arrangement of spins.
> This arrangement more accurately resembles the state of my material at
> room temperature and strong external magnetic field.
> I mention this because one reason for zero dipole term might be
> antiferromagnetic arrangement of spins. In such an arrangement
> contributions of neighbouring spins to dipole tensor could cancel one
> another.)
>
> Best regards.
>
> Gregor
>
> Gregor Mali
> National Institute of Chemistry
> Ljubljana, Slovenia
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