[Pw_forum] Help: the error of computaion single atom

Eyvaz Isaev eyvaz_isaev at yahoo.com
Sat Oct 14 16:16:46 CEST 2006


Hi, 

Sorry interfering, but it seems you forgot a very
important keyword, "occupations=XXXX". Your system is
considered as a semiconductor until you did not
specify  an occupations technique. You can use either
tetrahedra  or smearing technique with additional
keywords.

By the way the problem was discussed before and
presumably it is a good idea to check the forum
archive  before submitting a question.

Bests,
Eyvaz.

--- Xunlei Ding <ding at sissa.it> wrote:

> Hi,
> 
> If you are calculating for free N atom, I think you
> may have made some
> mistakes.
> 
> The first question:
> N atom has 5 valence electrons. So it can't be
> calculated with spin=1,
> because it has at least one unpaired electrons.
> 
> The second question:
> Total_magnatization= (number of unpaired electrons)/
> (total number of
> electrons), and starting_magnetization is the
> initial value of it.
> For spin=2 calculation, the starting_magnetization
> must be set with a
> nonzero value.
> As for N, it has 5 valence electrons in which 3
> electrons are unpaired.
> So it is reliable to set
> starting_magnetization(1)=3/5=0.6 . Actually
> other nonzero value will also work.
> And, for N atom, multiplicity=4, not 3.
> 
> btw: maybe nosym is needed in calculation of only
> one atom.
> 
> Yours,
> Ding
> 
> shangyi wrote:
> 
> > Dear all:
> > I'm a newer of pwscf(3.1.1) and troubled by the
> error of computation
> > single N atom energy! I computed the N atom
> without spin using the
> > following input:
> >
>
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > &control
> > calculation = 'scf'
> > restart_mode='from_scratch',
> > prefix='N.atom',
> > pseudo_dir = '/home/pub/pw/pseudo/',
> > outdir='/home/shyma/tmp/'
> > /
> > &system
> > ibrav= 1, celldm(1) =20, nat= 1, ntyp= 1,
> > ecutwfc =40,
> > /
> > &electrons
> > diagonalization='cg'
> > mixing_mode = 'plain'
> > mixing_beta = 0.7
> > conv_thr = 1.0d-8
> > /
> > ATOMIC_SPECIES
> > N 14.0067 N.pbe-rrkjus.UPF
> > ATOMIC_POSITIONS
> > N 0 0 0
> > K_POINTS AUTOMATIC
> > 1 1 1 0 0 0
> >
>
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > and it stop with the error:
> > WARNING: integrated charge= 4.30000000, expected=
> 5.00000000
> >
>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > from electrons : error # 1
> > charge is wrong
> >
>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > I have searched the maillist, but the information
> I got didn't solve
> > my problem, so what's wrong with my input file and
> how to correct it?
> > Another question is that I added the keyword
> "nspin=2, multiplicity=3"
> > when I want to computate the N atom with spin, it
> stoped and displayed
> > "some starting_magnetization MUST be set". The
> INPUT_PW says that
> > "multiplicity fixes the final value of the
> magnetization".
> > So is it need the starting_magnetization value
> when I have already set
> > the multiplicity? If it's needed, what's the
> meaning of
> > starting_magnetization and how ot set its value?
> > Any advice is appreciated!
> > Best wishes!
> > shuix
> >
> >
>
------------------------------------------------------------------------
> > Mp3·è¿ñËÑ-иèÈȸè¸ßËÙÏÂ
> >
>
<http://music.yahoo.com.cn/?source=mail_mailbox_footer>
> 
> 
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