[QE-users] Iron ibrav=3 bad magnetic moment in a large cell

[Christian helman]

Hi Paolo,
I attach both the input file and the output. As you see in the output
file the magnetics moments are not equals, as it should be.
Thanks in advance

Christian

El sáb, 26 ago 2023 a las 7:42, Paolo Giannozzi
(<paolo.giannozzi at uniud.it>) escribió:
>
> May you please provide the input files? Paolo
>
> On 17/08/2023 16:43, Christian helman wrote:
> > [You don't often get email from christian.helman at gmail.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> >
> > Hi
> > I'm having a problem with the calculation of a cell with ibrav=-3 (also 3)
> > I want to do a doping calculation in Fe-BCC, so I start with the unit
> > cell of the Iron bcc and then i duplicate it.
> > To start the calculation for the unit cell of iron the parameters i
> > use (among others) are:
> > ibrav = -3, celldm(1)= 5.4235161, nat= 1, ntyp= 1, ecutwfc=50,
> > occupations='smearing', smearing='mp', degauss=0.02,
> > with only one Fe atom at origin. The pseudopotencial is the PAW type
> > of Dal Corso.
> >
> > All works well! correct magnetic moment (2.13) and expected charge density.
> > Then i duplicate the cell parameter -> celldm(1)=10,8470322 and add
> > the corresponding atoms (of course nat=8)
> > ATOMIC_POSITIONS (crystal)
> >   Fe 0.0 0.0 0.0
> >   Fe 0.0 0.0 0.5
> >   Fe 0.0 0.5 0.0
> >   Fe 0.5 0.0 0.0
> >   Fe 0.5 0.5 0.5
> >   Fe 0.5 0.5 0.0
> >   Fe 0.5 0.0 0.5
> >   Fe 0.0 0.5 0.5
> >
> > Except celldm, nat and Kpoints (half of the orginal) the rest of the
> > input remains unchanged.
> > At the beginning of the output file, it correctly recognizes the 48
> > symmetry operations.
> > But the results are not correct. To start, the magnetic moment and
> > charges are different for each Fe atom.
> > I copy part of the output:
> >
> > Magnetic moment per site  (integrated on atomic sphere of radius R)
> >       atom   1 (R=0.179)  charge=  6.4398  magn=  1.6308
> >       atom   2 (R=0.179)  charge=  6.4428  magn=  1.4742
> >       atom   3 (R=0.179)  charge=  6.4428  magn=  1.4742
> >       atom   4 (R=0.179)  charge=  6.4428  magn=  1.4742
> >       atom   5 (R=0.179)  charge=  6.4428  magn=  1.4742
> >       atom   6 (R=0.179)  charge=  6.4397  magn=  1.6341
> >       atom   7 (R=0.179)  charge=  6.4397  magn=  1.6341
> >       atom   8 (R=0.179)  charge=  6.4397  magn=  1.6341
> >
> > I check the structure with xcrysden, distance and number of neighbours
> > are correct.
> > Am I doing something wrong? or there is a bug ?
> > Thanks in advance
> >
> > Christian
> >
> > --
> > Dr. Christian Helman
> > Div. Física de Superficies - Gerencia de Física
> > Centro Atómico Bariloche -CNEA
> > Ezequiel Bustillos 9,500 Km - CP 8400
> > San Carlos de Bariloche
> > Provincia de Rio Negro, Argentina
> > Tel:++54-294-444-5100 int 5375
> > _______________________________________________
> > The Quantum ESPRESSO community stands by the Ukrainian
> > people and expresses its concerns about the devastating
> > effects that the Russian military offensive has on their
> > country and on the free and peaceful scientific, cultural,
> > and economic cooperation amongst peoples
> > _______________________________________________
> > Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> > users mailing list users at lists.quantum-espresso.org
> > https://lists.quantum-espresso.org/mailman/listinfo/users
>
> --
> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216



-- 
Dr. Christian Helman
Div. Física de Superficies - Gerencia de Física
Centro Atómico Bariloche -CNEA
Ezequiel Bustillos 9,500 Km - CP 8400
San Carlos de Bariloche
Provincia de Rio Negro, Argentina
Tel:++54-294-444-5100 int 5375
-------------- next part --------------
A non-text attachment was scrubbed...
Name: iron.in
Type: application/octet-stream
Size: 745 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20230828/adee28fd/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: iron.out
Type: application/octet-stream
Size: 59778 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20230828/adee28fd/attachment-0001.obj>