[Pw_forum] anatase errors

Safa Alzaim safa.alzaim at gmail.com
Sat Nov 7 00:16:10 CET 2015


Many thanks, Giovanni, for your explanation. Unfortunately, I am still
getting errors. What could be the issue with the code below? I've checked
all the values.
Thanks,
Safa

&CONTROL
                       title = anatase1 ,
                 calculation = 'scf' ,
                restart_mode = 'from_scratch' ,
                  wf_collect = .true. ,
                      outdir = '/home/osboxes/qe/PWgui-5.2.1/' ,
                      wfcdir = '/home/osboxes/qe/PWgui-5.2.1/' ,
                  pseudo_dir = '/home/osboxes/qe/mypseudo/' ,
                      prefix = 'anatasetry1' ,
 /
 &SYSTEM
                       ibrav = 7,
                           A = 3.73 ,
                           C = 9.37 ,
                         nat = 6,
                        ntyp = 2,
                     ecutwfc = 40 ,
                     ecutrho = 320 ,
 /
 &ELECTRONS
              conv_thr = 1.0d-8 ,
                 mixing_mode = 'plain' ,
             diagonalization = 'david' ,
 /
ATOMIC_SPECIES
   Ti   46.86700  Ti.blyp-sp-hgh.UPF
    O   15.99400  O.blyp-hgh.UPF
ATOMIC_POSITIONS crystal
   Ti      0.000000000    0.000000000    0.000000000
   Ti      0.000000000    0.500000000    0.250000000
    O      0.000000000    0.000000000    0.208000000
    O       0.000000000    0.000000000   -0.208000000
    O       0.000000000      0.500000000    0.458000000
    O         0.000000000    0.500000000    0.292000000
K_POINTS automatic
  2  2  1   1 1 1







On Thu, Nov 5, 2015 at 9:00 AM, Giovanni Cantele <
giovanni.cantele at spin.cnr.it> wrote:

> Dear Safa,
>
> the errors you get is because you input the TiO2 anatase primitive unit
> cell, but include also periodic replicas of some atoms, that means that as
> the scf cycle starts, some atoms overlap and it will never converge!
>
> For example:
>     Ti      0.000000000    0.000000000    0.000000000
> and
>     Ti      3.730000000    0.000000000    0.000000000
> are obtained one from the other through a lattice translation (a,0,0) and
> so they cannot be included both in the ATOMIC_POSITIONS card if the A and C
> parameters specify the crystal primitive cell.
>
> If you want to use the cif file with VESTA, before exporting the xyz
> coordinates you must be sure that only the atoms in the primitive cell are
> shown. However, you can also look through lot of papers published
> on TiO2 anatase and related systems. If you do so, you discover that the
> unit cell contains two TiO units with Ti ions at 0,0,0 and (0, 1/2 , 1/4)
> and O ions at (0,0,u), (0,0,-u), (0,1/2 ,u+1/4 ) and (0,1/2 , 1/2-u) with
> u=0.208.
> This coordinates are in crystal units.
>
>
> Giovanni
>
> --
>
> Giovanni Cantele, PhD
> CNR-SPIN
> c/o Dipartimento di Fisica
> Universita' di Napoli "Federico II"
> Complesso Universitario M. S. Angelo - Ed. 6
> Via Cintia, I-80126, Napoli, Italy
> e-mail: giovanni.cantele at spin.cnr.it
> Phone: +39 081 676910
> Skype contact: giocan74
>
> ResearcherID: http://www.researcherid.com/rid/A-1951-2009
> Web page: http://people.na.infn.it/~cantele
>
> > On 05 Nov 2015, at 02:43, Safa Alzaim <safa.alzaim at gmail.com> wrote:
> >
> > Hello All,
> >     I am new at QE, so please excuse the simplicity of my questions. I
> am working with bulk TiO2 anatase. I downloaded a cif, and then used Vesta
> to convert the data to xyz coordinates. However, I get the 31 atom unit
> cell instead of the primitive cell. In any case, I entered A and C values.
> I keep getting errors when I try to run the file. If anybody could help,
> I'd really appreciate it.
> > Thanks!
> > Safa
> >
> >
> > &CONTROL
> >                        title = anatase1 ,
> >                  calculation = 'scf' ,
> >                 restart_mode = 'from_scratch' ,
> >                   wf_collect = .true. ,
> >                       outdir = '/home/osboxes/qe/PWgui-5.2.1/' ,
> >                       wfcdir = '/home/osboxes/qe/PWgui-5.2.1/' ,
> >                   pseudo_dir = '/home/osboxes/qe/mypseudo/' ,
> >                       prefix = 'anatasetry1' ,
> >  /
> >  &SYSTEM
> >                        ibrav = 7,
> >                            A = 3.73 ,
> >                            C = 9.37 ,
> >                          nat = 31,
> >                         ntyp = 2,
> >                      ecutwfc = 40 ,
> >                      ecutrho = 320 ,
> >  /
> >  &ELECTRONS
> >               conv_thr = 1.0d-8 ,
> >                  mixing_mode = 'plain' ,
> >              diagonalization = 'david' ,
> >  /
> > ATOMIC_SPECIES
> >    Ti   46.86700  Ti.blyp-sp-hgh.UPF
> >     O   15.99400  O.blyp-hgh.UPF
> > ATOMIC_POSITIONS angstrom
> >    Ti      0.000000000    0.000000000    0.000000000
> >    Ti      0.000000000    0.000000000    9.370000000
> >    Ti      0.000000000    3.730000000    0.000000000
> >    Ti      0.000000000    3.730000000    9.370000000
> >    Ti      3.730000000    0.000000000    0.000000000
> >    Ti      3.730000000    0.000000000    9.370000000
> >    Ti      3.730000000    3.730000000    0.000000000
> >    Ti      3.730000000    3.730000000    9.370000000
> >    Ti      1.865000000    1.865000000    4.685000000
> >    Ti      0.000000000    1.865000000    2.342500000
> >    Ti      3.730000000    1.865000000    2.342500000
> >    Ti      1.865000000    0.000000000    7.027500000
> >    Ti      1.865000000    3.730000000    7.027500000
> >     O      0.000000000    0.000000000    1.874000000
> >     O      0.000000000    3.730000000    1.874000000
> >     O      3.730000000    0.000000000    1.874000000
> >     O      3.730000000    3.730000000    1.874000000
> >     O      1.865000000    1.865000000    6.559000000
> >     O      0.000000000    1.865000000    4.216500000
> >     O      3.730000000    1.865000000    4.216500000
> >     O      1.865000000    0.000000000    8.901500000
> >     O      1.865000000    3.730000000    8.901500000
> >     O      1.865000000    0.000000000    5.153500000
> >     O      1.865000000    3.730000000    5.153500000
> >     O      0.000000000    1.865000000    0.468500000
> >     O      3.730000000    1.865000000    0.468500000
> >     O      1.865000000    1.865000000    2.811000000
> >     O      0.000000000    0.000000000    7.496000000
> >     O      0.000000000    3.730000000    7.496000000
> >     O      3.730000000    0.000000000    7.496000000
> >     O      3.730000000    3.730000000    7.496000000
> > K_POINTS automatic
> >   2  2  1   1 1 1
> >
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>
>
>
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