[Pw_forum] fixed spin moment calculation

[yumin qian]

Sorry for confuse you ,  After checking the input and output file , I found
that I also did  a LiVO2 crystal calcualtion with the same problem, the
input file I posted is for LiNiO2 and the output file I posted  is for
LiVO2  , here is the complete input and output file from the
same calcualtion

&control
    calculation='scf'
    restart_mode='from_scratch' ,
    pseudo_dir = '~/software/espresso-4test/pseudo',
    outdir='outscf'
    nstep=60
    prefix='AFM-type'
    tstress = .true.
    tprnfor = .true.
    wf_collect=.true.
 /
 &system
    ibrav = 0, nat=16 , ntyp= 4,
    ecutwfc = 35.0, ecutrho = 300.0,
    occupations='tetrahedra',
    nspin=2,constrained_magnetization='atomic',lambda=5.0,
starting_magnetization(1)= 0.0,
starting_magnetization(2)= 1.8,
starting_magnetization(3)=-1.8,
starting_magnetization(4)= 0.0,
lda_plus_u=.true.
Hubbard_U(1)=0.0
Hubbard_U(2)=3.0
Hubbard_U(3)=3.0
Hubbard_U(4)=0.0

 /
 &electrons
    diagonalization='david',
    conv_thr = 1.0e-7,
    mixing_beta = 0.5,
 /

ATOMIC_SPECIES
Li    6.914      Li.pbe-n-mt_bw.UPF
V1  50.9415   V.pbe-n-van.UPF
V2  50.9415   V.pbe-n-van.UPF
O   15.9994   O.pbe-van_bm.UPF
ATOMIC_POSITIONS {crystal}
Li  0.0000000000000000  0.0000000000000000  0.0
Li  0.0000000000000000  0.0000000000000000  0.5
Li  0.5000000000000000  0.5000000000000000  0.0
Li  0.5000000000000000  0.5000000000000000  0.5
V1  0.0000000000000000  0.5000000000000000  0.25
V2  0.0000000000000000  0.5000000000000000  0.75
V2  0.5000000000000000  0.0000000000000000  0.25
V1  0.5000000000000000  0.0000000000000000  0.75
O   0.2354848230051515  0.0000000000000000  0.35287967
O   0.2354848230051515  0.0000000000000000  0.85287967
O   0.7354848230051516  0.5000000000000000  0.35287967
O   0.7354848230051516  0.5000000000000000  0.85287967
O   0.7645151769948484  0.0000000000000000  0.14712033
O   0.7645151769948484  0.0000000000000000  0.64712033
O   0.2645151769948484  0.5000000000000000  0.14712033
O   0.2645151769948484  0.5000000000000000  0.64712033
K_POINTS {automatic}
  8 8 6  1 1 1
CELL_PARAMETERS (alat)
    9.903876    0.000000    0.000000
    0.000000    5.622988    0.000000
   -6.542514    0.000000   20.135790

the output file gives

 ==============================================================================
     atom number    4 relative position :    0.1697   0.2839   1.0166
     charge :     0.065485
     magnetization :          0.000000
     magnetization/charge:    0.000000
     constrained moment :     0.000000

 ==============================================================================

 ==============================================================================
     atom number    5 relative position :   -0.1652   0.2839   0.5083
     charge :     2.371448
     magnetization :          1.554551
     magnetization/charge:    0.655528
     constrained moment :     1.800000


I also  changed lambda from 1 to 5 and the   final magnetic moment changed
from 1.55 to 1.50
so the parameter lambda seems  have no impact on the final magnetic moment,
there should be something wrong with my calcualtion but I can't spot this
error.


2009/3/12 Gabriele Sclauzero <sclauzer at sissa.it>

> Dear Yumin Qian,
>
>    There's something strange in this output. I think that atom number 5
> should be a Ni
> one, since you were interested in the magnetization of that species, but
> then, why is the
> charge around that atom only about 2.5? Ni should have 10 electrons in
> valence, so I would
> expect to get a number around 10 for the charge (unless the atom goes in a
> very ionized
> state, but that seems highly unprobable to me).
> Are you sure PPs and all the rest is OK?
>
>
> GS
>
> yumin qian wrote:
> > thanks for your reply ,I  changed the lambda=5.0 and used
> >    occupations='tetrahedra'  but the magnetization still did not
> > converge to the initial value ,but the total energy converged.
> > I do know what is the problem.
> >
>  ==============================================================================
> >      >      atom number    5 relative position :   -0.1652   0.2839
> 0.5083
> >      >      charge :     2.373353
> >      >      magnetization :          1.544423
> >      >      magnetization/charge:    0.650735
> >      >      constrained moment :     1.800000
> >      >
> >      >
> >
>  ==============================================================================
> >      > the output file gives a magnetic moment of 1.5444 ,how should I do
> to
> >      > make the calculation  converge to the starting_magnetization 1.8 ?
> >
>
> --
>
>
> o ------------------------------------------------ o
> | Gabriele Sclauzero, PhD Student                  |
> | c/o:   SISSA & CNR-INFM Democritos,              |
> |        via Beirut 2-4, 34014 Trieste (Italy)     |
> | email: sclauzer at sissa.it                         |
> | phone: +39 040 3787 511                          |
> | skype: gurlonotturno                             |
> o ------------------------------------------------ o
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>



-- 
Sincerely Y. M. Qian
Lab.of Condensed Matter Theory and Materials Computation
Institute of Physics
Chinese Academy of Sciences
Tel:  + 8610 8264 9147
E-Mail:yuminqian at gmail.com <E-Mail%3Ayuminqian at gmail.com>
P.O.Box 603   Beijing 100190
China
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20090312/989048e4/attachment.html>