Dear Claudia,
>How did you define your unit cell in the input for the pw.x runs?
>
>If you used ibrav=0
>and then specified the lattice vectors using:
>CELL_PARAMETERS { cubic | hexagonal }
> a(1,1) a(2,1) a(3,1)
> a(1,2) a(2,2) a(3,2)
> a(1,3) a(2,3) a(3,3)
>
>I am afraid this is the source of your problem running q2r.x
>
>The q2r program, as it is now written, reads in input dynamical
>matrices generated using ibrav=/=0 and uses the corresponding
>"automatic" choice for the lattice vector (generated by latgen).
I did not input in this way as you stated. I check the reference and find
that for Alpha_Ga structure, the spacegroup is Cmca and Gallium atoms are
in the 8f Wyckoff position, and y=0.1549 and z=0.081. So I set ibrav=9. The
following is my input file for PW.x run.
cat >Ga.scf.in <<EOF
Alpha_Ga
bco
&CONTROL
calculation='scf',
restart_mode='restart',
tstress=.t.,tprnfor=.t.,
PSEUDO_DIR='$PSEUDO_DIR/',
outdir='$TMP_DIR/',
/
&system
ibrav= 9, celldm(1) =8.42,celldm(2)=1.69468,celldm(3)=1.00168,
nat= 4, ntyp= 1,
ecutwfc =60.0,nosym=.t.,
occupations='smearing', smearing='methfessel-paxton', degauss=0.05
/
&ELECTRONS
conv_thr=1e-8,
mixing_beta=0.7
/
ATOMIC_SPECIES
Ga 69.723 PS_Ga.af
ATOMIC_POSITIONS {crystal}
Ga 0.8451 0.1549 0.0810
Ga 0.6549 0.3451 0.5810
Ga 0.3451 0.6549 0.4190
Ga 0.1549 0.8451 0.9190
K_POINTS {automatic}
8 8 8 0 0 0
EOF
I am just wondering how one can be confident with one's input.This is
extremely important.
Unfortunetaly, PWSCF doesn't perform the checking function. The only thing
we can do is trying to analyze using the output symmetry operation. In my
case, I did find 8 symmetry operation. But I am still not sure if my input
is correct.
Yanming
>best regards,
>Claudia
>
>__________________________________________________
>Dr. Claudia Bungaro
>Dept. of Physics and Astronomy, Rutgers University
>136 Frelinghuysen Road, Piscataway, NJ 08854-8019
>
>tel: +1 732 445 4197 fax: +1 732 445 4343
>email: bungaro at physics.rutgers.edu
>__________________________________________________
>
>
>On Thu, 28 Aug 2003, ma Yanming wrote:
>
> > Dear All,
> >
> > When I tried to calculate the force constant in Real space using q2r.x,
I
> > met the following error message:
> >
> > reading dyn.mat. from file Case_3.dyn
> > nqs= 2
> > q= 0.00000000 0.00000000 0.82109896
> > q= 0.00000000 0.00000000 -0.82109896
> > 1 1 2
> >
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > from init : error # 1
> > nc already filled
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > stopping ...
> >
> > I know if one chooses the wrong q points set to calculate the force
> > constant, then PWSCF will find the duplications.The error message will
> > occur as above. But I am confident that mine is not this case.
> >
> > My question is If my input atomic positions are wrong,will this error
> > message occur?
> > I still doubt about the input atomic coordinate for C-based
Orthorhombic
> > unit cell as my previous email. But for that email, nobody reply me.
> > Does anyone have the successful experiences in calculating the phonon
in
> > C_based orthorhombic unit cell?
> >
> > Any Comment?
> >
> > Thanks in advance.
> >
> > Yanming Ma PhD
> > Steacie Institute for Molecular Sciences,
> > National Research Councils of Canada.
> > 100 Sussex
> > K1A 0R6
> >
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> >
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