[Pw_forum] "Raman activities" do not converge
xirainbow
nkxirainbow at gmail.com
Thu May 30 17:29:03 CEST 2013
Dear Paolo Giannozzi:
Thank you very much for your suggestion:)
> I would carefully check the output instead.
I carefully check the output of ph.x.
I found the "Raman tensor" does not converge. Except the
"Raman tensor", I did not find any abnormity. I increased the kmesh
from 14*14*14 to 20*20*20, but it did not help. I attache the
"ecutwfc=100, 110" results.
I changes the pseudopotential from "C.pw-mt_fhi.UPF" to
"C.pz-hgh.UPF" and get the expected "Raman activity" for different
ecutwfc. However, the results of "ecutwfc=110" are still higher than
others.
The following is my results.
Using "C.pw-mt_fhi.UPF" :
ecutwfc(Ry) Freq(cm-1) Raman activity(A^4/amu)
65 1330.65 68.9754
100 1330.23 68.9674
110 1330.50 3066.0811
120 1330.48 15.1570
130 1330.47 68.9545
140 1330.48 68.9536
150 1330.48 68.9541
Using "C.pz-hgh.UPF" :
ecutwfc(Ry) Freq(cm-1) Raman activity(A^4/amu)
70 1330.78 69.6225
90 1341.85 70.0144
100 1333.32 70.1650
110 1337.38 87.7369
120 1339.90 69.9051
130 1339.60 69.9249
140 1338.35 69.9469
150 1337.71 69.9402
On Thu, May 30, 2013 at 1:27 AM, Paolo Giannozzi
<paolo.giannozzi at uniud.it> wrote:
>
> I would carefully check the output instead.
> Two values for the Raman activity are clearly
> outliers in a set of well-behaving data points.
> They are highly suspect.
>
> P.
>
> On Wed, 2013-05-29 at 09:43 -0700, Sanjeev Gupta wrote:
> > Dear Wang
> >
> >
> > In my guess, the converging mostly depends on choosing
> > pseudopotential, so may be it is the problem, that you are not getting
> > converge Raman activity.
> > Otherhand, can you check your structure as well as, but i am not sure.
> >
> >
> > Best
> > Sanjeev
> >
> >
> > On Wed, May 29, 2013 at 5:22 AM, xirainbow <nkxirainbow at gmail.com>
> > wrote:
> > Dear all:
> > I calculated the "Raman activity" of
> > diamond(Carbon) using QE-5.0.
> > The "Raman activity" changes too much with
> > ecutwfc.
> > Could you give me some help?
> >
> >
> > Calculational results of "Raman activity variation with
> > ecutwfc" ("14*14*14 kmesh).
> > ecutwfc(Ry) Freq(cm-1) Raman
> > activity(A^4/amu)
> > 65 1330.23 68.9754
> > 100 1330.65 68.9674
> > 110 1330.50 3066.0811
> > 120 1330.48 15.1570
> > 130 1330.47 68.9545
> >
> >
> > The following is input of pw.x and ph.x:
> > INPUT of SCF:
> > &control
> > calculation='scf',
> > disk_io='low',
> > restart_mode='from_scratch',
> > prefix='diamond.$i'
> > pseudo_dir = '/home/lykong/hwang/espresso-5.0/pseudo',
> > outdir='/home/lykong/hwang/tmp'
> > /
> > &system
> > ibrav = 0, celldm(1) = 1.88972687777436, nat= 2, ntyp= 1,
> > ecutwfc = $i
> > /
> > &electrons
> > mixing_beta = 0.7
> > conv_thr = 1.0d-8
> > /
> > ATOMIC_SPECIES
> > C 12.01 C.pw-mt_fhi.UPF
> > ATOMIC_POSITIONS {crystal}
> > C 0.000000000 0.000000000 0.00000000
> > C 0.250000000 0.250000000 0.25000000
> > CELL_PARAMETERS
> > 1.758613117 1.758613117 0.000000000
> > 1.758613117 0.000000000 1.758613117
> > 0.000000000 1.758613117 1.758613117
> >
> >
> >
> >
> > INPUT of PHONON:
> > phonons of diamond at Gamma
> > &inputph
> > tr2_ph=1.0d-14,
> > alpha_mix=0.7
> > prefix='diamond.$i'
> > epsil=.true.,
> > lraman=.true.,
> > amass(1)=12.01,
> > outdir='/home/lykong/hwang/tmp'
> > fildyn='diamond.$i.dynG',
> > reduce_io=.TRUE.
> > /
> > 0.0 0.0 0.0
> >
> >
> >
> >
> >
> > --
> > ____________________________________
> > Hui Wang
> > School of physics, Fudan University, Shanghai, China
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
> >
> >
> >
> >
> > --
> > With Best Regards,
> >
> >
> > ------------------------------------
> > Dr. Sanjeev Kumar Gupta
> > Fulbright Post-Doctoral Scholar
> > Dept. of Physics
> > Michigan Technological University
> > 1400 Townsend Drive, Houghton
> > MI 49931, USA
> > ------------------------------------
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
>
> --
> Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
--
____________________________________
Hui Wang
School of physics, Fudan University, Shanghai, China
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