[Pw_forum] Zn NC_PP from qe-forge

Giuseppe Mattioli giuseppe.mattioli at mlib.ism.cnr.it
Wed Oct 19 14:59:02 CEST 2011


Dear Yung Song
I think you've "kind of" understood...:-)
For example, only to be sure, you may try to calculate the ZnO lattice 
parameters at increasing wfc cutoffs (70, 80, 90, 100, ... Ry) and check when 
they become stable (i.e., converge of lattice parameters reached with respect 
to the wfc cutoff). This is probably the most important convergence test in 
your case.
Yours
Giuseppe

On Wednesday 19 October 2011 13:35:25 GAO Zhe wrote:
> If you are not farmiliar with convergence test, then it is so dangerous for
> your calculations, since your result can not be proved as self-consistents
> and reliable. This PPT may help you understand convergence test, even
> though it comes from CASTEP group:
> http://www.castep.org/CASTEP_talks_07/refson1.pdf
>
>
> --
> GAO Zhe
> CMC Lab, MSE, SNU, Seoul, S.Korea
>
>
> At 2011-10-19 19:17:54,"之王 改王" <songsongfc at yahoo.com.cn> wrote:
>
> Dear Giuseppe:
>   Hi, your adivce is great help for me. I have understood a lot since
> learning your adivce.I think your means that the parameters change
> relatively small between different wfc cut off(such as 67 and 60) ,it note
> stable? Is it right? I will try and follow you and Paolo's advice.
>
> Best
> Regrads.
> Yun Song,Kang
> Department Physical Science and Technology of Inner Mongolia University.
>
> ---11年10月16日,周日,giuseppe.mattioli at mlib.ism.cnr.it<giuseppe.mattioli at mlib.is
>m.cnr.it> 写道:
>
>
> 发件人:giuseppe.mattioli at mlib.ism.cnr.it <giuseppe.mattioli at mlib.ism.cnr.it>
> 主题: Re: [Pw_forum] Zn NC_PP from qe-forge
> 收件人:pw_forum at pwscf.org
> 日期: 2011年10月16日,周日,下午8:33
>
>
>
> Dear Yung Song
> What Paolo means is that you should perform a series of calculation
> (for example on the ZnO cell) by raising the wfc cutoff. When all the
> parameters (Energy, forces, eigenvalues...) become stable between two
> calculations with different cutoff, then you have reached convergence
> with respect to the wfc basis set. How much stable? Well... It depends
> on your purposes (and on your experience of a given system);
> calculations are sometimes art more than science...:-)
> Hope this suggestion helps more than the previous one, but listen to
> Paolo: do not start production runs unless you've really understood
> them.
>
> Giuseppe
>
> Giuseppe Mattioli
> ISM-CNR
> Italy
>
> Quoting ?? ?? <songsongfc at yahoo.com.cn>:
> > Dear Paolo and Giuseppe:
> > Thanks for your help. It seems to be necessary to learn the mean of
> > concergence.
> >
> > Best
> > Regards
> >
> > Yun Song,Kang
> >
> > Department Physical Science and Technology of  Inner Mongolia University.
> >
> > --- 11?10?14????, Giuseppe Mattioli <giuseppe.mattioli at mlib.ism.cnr.it>
> > ???
> >
> > ???: Giuseppe Mattioli <giuseppe.mattioli at mlib.ism.cnr.it>
> > ??: Re: [Pw_forum] Zn NC_PP from qe-forge
> > ???: "PWSCF Forum" <pw_forum at pwscf.org>
> > ??: 2011?10?14?,??,??9:12
> >
> >
> > Dear Yun Song
> > A 62Ry cutoff could be quite poor both in the case of your NC Zn (it
> > contains a quite deep 3d shell) and for your NC O.
> > You should reach concergence with respect to the wf cutoff before
> > attempting to perform phonon calculations.
> > HTH
> > Giuseppe
> >
> > On Friday 14 October 2011 15:03:48 ?? ?? wrote:
> >> Hi,
> >>   Recently,I generate Zn NC-PP using the PP library from qe-forge
> >> project. I want to generate Zn.pz-nc.UPF using ld1.x.
> >> My Zn.-nc.in is followed:
> >>  &input
> >>    title='Zn',
> >>    zed=30.,
> >>    rel=0,
> >>    config='[Ar] 4s2.0 4p0.0 3d10.0',
> >>    iswitch=3,
> >>    dft='PZ'
> >>  /
> >>  &inputp
> >>    pseudotype=2,
> >>    file_pseudopw='Zn.pz-nc.UPF',
> >>    author='TM',
> >>    lloc=0,
> >>    nlcc=.true.,
> >>    tm=.true.
> >>  /
> >> 3
> >> 4P  2  1  0.00  0.00  2.30  2.30  0.0
> >> 3D  3  2 10.00  0.00  2.30  2.30  0.0
> >> 4S  1  0  2.00  0.00  2.30  2.30  0.0
> >>
> >>
> >> And I calculate ZnO vc-relax using Zn.pz-nc.UPF and O.pz-mt.UPF,
> >> the theory is a=6.223 c/a=1.614, after calculating vc-relax is a=6.191
> >> c/a=1.614 with ecutwfc=62Ry.
> >>
> >> However, No matter how I try to calculate,the phonon frequency is
> >> negative
> >>
> >> The scf and ph file is followed:
> >> &CONTROL
> >>                  calculation = 'scf' ,
> >>                 restart_mode = 'from_scratch' ,
> >>                       outdir = '/root/ZnO/915-phonon' ,
> >>                   pseudo_dir = '/root/pseudopotential' ,
> >>                       prefix = 'ZnO' ,
> >>                etot_conv_thr = 1.0D-5 ,
> >>                forc_conv_thr = 1.0D-4 ,
> >>                      tstress = .true. ,
> >>                      tprnfor = .true. ,
> >>  /
> >>  &SYSTEM
> >>                        ibrav = 4,
> >>                    celldm(1) = 6.191,
> >>                    celldm(3) = 1.614,
> >>                          nat = 4,
> >>                         ntyp = 2,
> >>                      ecutwfc = 62 ,
> >>  /
> >>  &ELECTRONS
> >>                     conv_thr = 1.0d-10 ,
> >>                  mixing_mode = 'plain' ,
> >>                  mixing_beta = 0.6 ,
> >>              diagonalization = 'david' ,
> >>  /
> >> ATOMIC_SPECIES
> >>    Zn   65.40900  Zn.pz-nc.UPF
> >>     O   15.99940  O.pz-mt.UPF
> >> ATOMIC_POSITIONS crystal
> >> Zn       0.333333333   0.666666667  -0.000036499   1 1 1
> >> Zn       0.666666667   0.333333333   0.499963501   1 1 1
> >> O        0.333333333   0.666666667   0.379036499   1 1 1
> >> O        0.666666667   0.333333333   0.879036499   1 1 1
> >> K_POINTS automatic
> >>   4 4 4   1 1 1
> >>
> >>
> >>
> >> phonons of ZnO
> >>  &INPUTPH
> >>                       outdir = '/root/ZnO/915-phonon' ,
> >>                       prefix = 'ZnO' ,
> >>                       fildyn = 'ZnO_IR.dyn' ,
> >>                     fildvscf = 'ZnO.dv' ,
> >>                        ldisp = .true.,
> >>                          nq1 = 4 ,
> >>                          nq2 = 4 ,
> >>                          nq3 = 4 ,
> >>                        epsil = .false.,
> >>                         elph = .false.,
> >>                         fpol = .false. ,
> >>                      recover = .false. ,
> >>                     amass(1) = 65.4090,
> >>                     amass(2) = 15.9994,
> >>                       tr2_ph = 1.0d-12 ,
> >>  /
> >>
> >> Best
> >> Regards
> >> Yun Song,Kang
> >>
> >> Department Physical Science and Technology of  Inner Mongolia
> >> University.
> >
> > --
> > ********************************************************
> > - Article premier - Les hommes naissent et demeurent
> > libres et ègaux en droits. Les distinctions sociales
> > ne peuvent être fondèes que sur l'utilitè commune
> > - Article 2 - Le but de toute association politique
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> > imprescriptibles de l'homme. Ces droits sont la libertè,
> > la propriètè, la sùretè et la rèsistance à l'oppression.
> > ********************************************************
> >
> >    Giuseppe Mattioli
> >    CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
> >    v. Salaria Km 29,300 - C.P. 10
> >    I 00015 - Monterotondo Stazione (RM)
> >    Tel + 39 06 90672836 - Fax +39 06 90672316
> >    E-mail: <giuseppe.mattioli at ism.cnr.it>
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-- 
********************************************************
- Article premier - Les hommes naissent et demeurent
libres et ègaux en droits. Les distinctions sociales
ne peuvent être fondèes que sur l'utilitè commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et 
imprescriptibles de l'homme. Ces droits sont la libertè,
la propriètè, la sùretè et la rèsistance à l'oppression.
********************************************************

   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
   v. Salaria Km 29,300 - C.P. 10                
   I 00015 - Monterotondo Stazione (RM)          
   Tel + 39 06 90672836 - Fax +39 06 90672316    
   E-mail: <giuseppe.mattioli at ism.cnr.it>



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