[Pw_forum] BaRuO3 forces are zero always for any celldm(1)

SRKC Sharma Yamijala sharmajncasr at gmail.com
Thu Sep 25 12:07:24 CEST 2014


Dear all,

I am trying to optimize the BaRuO3 perovskite structure (after the
completion of the usual convergence tests). Through lattice parameter
optimization (ev.x) I found celldm(1) should be 7.61 Bohr.

When I have tried to do vc-relax, I got the message "noncollinear stress +
GGA not implemented". Following the previous post (
http://qe-forge.org/pipermail/pw_forum/2011-April/094510.html) with similar
message, I have tried to just relax the structure (instead of vc-relax) by
giving the below flags in Ions section.

!                   bfgs_ndim = 3,
!           pot_extrapolation = "second_order",
!           wfc_extrapolation = "second_order",

But, always I got zero forces (I have varied celldm(1) from 6.0 to 7.61 to
check).

Would it possible to suggest how can I relax the structure and proceed
further?

Thanking you for your support,
Sincerely,
Sharma.

Input file is given below. I have used espresso 5.0 version
 &CONTROL
                       title = 'baruo3_3c' ,
                 calculation = 'relax' ,
                restart_mode = 'from_scratch' ,
                      outdir = './tmp/' ,
                  pseudo_dir = '/sfs3/home/raja/dasari/BaRuO3/',
                      prefix = 'baruo3_3c' ,
               etot_conv_thr = 1.0D-5 ,
               forc_conv_thr = 1.0D-4 ,
                       nstep = 200 ,
                   verbosity = 'high' ,
 /
 &SYSTEM
                       ibrav = 1,
                   celldm(1) = 7.61 ,
                         nat = 5,
                        ntyp = 3,
                     ecutwfc = 70 ,
                     ecutrho = 560,
                 occupations = 'smearing' ,
                     degauss = 0.01,
                    smearing = 'marzari-vanderbilt' ,
!                    lspinorb = .true.
!                    noncolin = .true.
 /
 &ELECTRONS
            electron_maxstep = 150,
                    conv_thr = 1.D-6 ,
                 mixing_beta = 0.7 ,
 /
 &IONS
                ion_dynamics = 'bfgs' ,
!                   bfgs_ndim = 3,
!           pot_extrapolation = "second_order",
!           wfc_extrapolation = "second_order",
 /
 &CELL
 /

ATOMIC_SPECIES
   Ba   137.3270 Ba.pbe-nsp-van.UPF
   Ru   101.0700 Ru.pbe-n-van.UPF
    O   15.99940  O.pbe-van_bm.UPF

ATOMIC_POSITIONS crystal
 Ba                 0.00000000    0.00000000    0.00000000
 Ru                 0.50000000    0.50000000    0.50000000
 O                  0.00000000    0.50000000    0.50000000
 O                  0.50000000    0.00000000    0.50000000
 O                  0.50000000    0.50000000    0.00000000

K_POINTS automatic
  6 6 6   1 1 1









********************************************************
*Chaitanya Sharma,*
*Prof. Pati'*s group,
Chemistry and Physics Materials unit,
JNCASR, BANGLORE,
Lab:: (080-2208) 2581, 2809
https://sites.google.com/site/sharmasrkcyamijala/
*********************************************************

On Thu, Sep 25, 2014 at 2:15 PM, SRKC Sharma Yamijala <
sharmajncasr at gmail.com> wrote:

> Dear all,
>
> I am trying to optimize the BaRuO3 perovskite structure (after the
> completion of the usual convergence tests). Through lattice parameter
> optimization (ev.x) I found celldm(1) should be 7.61 Bohr.
>
> When I have tried to do vc-relax, I got the message "noncollinear stress
> + GGA not implemented". Following the previous post (
> http://qe-forge.org/pipermail/pw_forum/2011-April/094510.html) with
> similar message, I have tried to just relax the structure (instead of
> vc-relax) by giving the below flags in Ions section.
>
> !                   bfgs_ndim = 3,
> !           pot_extrapolation = "second_order",
> !           wfc_extrapolation = "second_order",
>
> But, always I got zero forces (I have varied celldm(1) from 6.0 to 7.61 to
> check).
>
> Would it possible to suggest how can I relax the structure and proceed
> further?
>
> Thanking you for your support,
> Sincerely,
> Sharma.
>
> Input file is given below:
>  &CONTROL
>                        title = 'baruo3_3c' ,
>                  calculation = 'relax' ,
>                 restart_mode = 'from_scratch' ,
>                       outdir = './tmp/' ,
>                   pseudo_dir = '/sfs3/home/raja/dasari/BaRuO3/',
>                       prefix = 'baruo3_3c' ,
>                etot_conv_thr = 1.0D-5 ,
>                forc_conv_thr = 1.0D-4 ,
>                        nstep = 200 ,
>                    verbosity = 'high' ,
>  /
>  &SYSTEM
>                        ibrav = 1,
>                    celldm(1) = 7.61 ,
>                          nat = 5,
>                         ntyp = 3,
>                      ecutwfc = 70 ,
>                      ecutrho = 560,
>                  occupations = 'smearing' ,
>                      degauss = 0.01,
>                     smearing = 'marzari-vanderbilt' ,
> !                    lspinorb = .true.
> !                    noncolin = .true.
>  /
>  &ELECTRONS
>             electron_maxstep = 150,
>                     conv_thr = 1.D-6 ,
>                  mixing_beta = 0.7 ,
>  /
>  &IONS
>                 ion_dynamics = 'bfgs' ,
> !                   bfgs_ndim = 3,
> !           pot_extrapolation = "second_order",
> !           wfc_extrapolation = "second_order",
>  /
>  &CELL
>  /
>
> ATOMIC_SPECIES
>    Ba   137.3270 Ba.pbe-nsp-van.UPF
>    Ru   101.0700 Ru.pbe-n-van.UPF
>     O   15.99940  O.pbe-van_bm.UPF
>
> ATOMIC_POSITIONS crystal
>  Ba                 0.00000000    0.00000000    0.00000000
>  Ru                 0.50000000    0.50000000    0.50000000
>  O                  0.00000000    0.50000000    0.50000000
>  O                  0.50000000    0.00000000    0.50000000
>  O                  0.50000000    0.50000000    0.00000000
>
> K_POINTS automatic
>   6 6 6   1 1 1
>
>
>
>
> ********************************************************
> *Chaitanya Sharma,*
> *Prof. Pati'*s group,
> Chemistry and Physics Materials unit,
> JNCASR, BANGLORE,
> Lab:: (080-2208) 2581, 2809
> https://sites.google.com/site/sharmasrkcyamijala/
> *********************************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140925/a37dab8b/attachment.html>


More information about the users mailing list