[Pw_forum] Different behavior in relax tasks (Marino Vetuschi Zuccolini)

[Marino Vetuschi Zuccolini]

Hi Cesar,

> Hi Marino,
>
> please, send your input file.

here the two simple input files I try to use to simulate the  
displacement of the Oxygen in ringwoodite mimicking your very recent  
paper (L. Li,1 R. M. Wentzcovitch, D.J. Weidner, and Cesar R. S. Da  
Silva - JGR 112, B05206, doi:10.1029/2006JB004546, 2007). The  
parameters for sensitive variables are far from the good values but  
the result I obtain now are deriving probably from a misusing of the  
available options.

All suggestion are welcomed,

m.


&control
     calculation='vc-relax'
     restart_mode='from_scratch',
     disk_io = 'minimal',
     tprnfor = .true.,
     tstress = .true.,
     prefix='ringwoodite.opt',
     pseudo_dir = '/sh/PWSCF_pseudo',
     outdir='./tmp/',
     verbosity = 'high',
/
&system
     ibrav=2,
     celldm(1)=15.9251789,
     nat=3,
     ntyp=3,
     nspin= 1,
     ecutwfc = 70.0,
     ecutrho = 280.0,
/
&electrons
     conv_thr =  1.0d-8
     mixing_beta = 0.7
/
&IONS
                         tempw = 300.,
/
&CELL
                cell_dynamics = 'damp-w' ,
                        press = 0.0 ,
                        wmass = 0.01 ,
/
ATOMIC_SPECIES
Mg  24.305  Mg.pz-n-vbc.UPF
O   15.999  O.pz-mt.UPF
Si  28.085  Si.pz-vbc.UPF
ATOMIC_POSITIONS  crystal
Si   0.12500   0.12500   0.12500 0 0 0
Mg   0.50000   0.50000   0.50000 0 0 0
O    0.24410   0.24410   0.24410
K_POINTS automatic
4 4 4 0.5 0.5 0.5

  &control
     calculation='relax'
     restart_mode='from_scratch',
     disk_io = 'minimal',
     tprnfor = .true.,
     tstress = .true.,
     prefix='ringwoodite.opt',
     pseudo_dir = '/sh/PWSCF_pseudo',
     outdir='./tmp/',
     verbosity = 'high',
/
&system
     ibrav=2,
     celldm(1)=15.9251789,
     nat=3,
     ntyp=3,
     nspin= 1,
     ecutwfc = 70.0,
     ecutrho = 280.0,
/
&electrons
     conv_thr =  1.0d-8
     mixing_beta = 0.7
/
   &IONS
                         tempw = 300.,
/
ATOMIC_SPECIES
Mg  24.305  Mg.pz-n-vbc.UPF
O   15.999  O.pz-mt.UPF
Si  28.085  Si.pz-vbc.UPF
ATOMIC_POSITIONS  crystal
Si   0.12500   0.12500   0.12500 0 0 0
Mg   0.50000   0.50000   0.50000 0 0 0
O    0.24410   0.24410   0.24410
K_POINTS gamma


On 11 Oct 2007, at 1:03, Cesar R.S. da Silva wrote:

>
>
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*******************************************************
Marino Vetuschi Zuccolini
zucco at dipteris.unige.it
Researcher / Geochemist
Laboratory of Geochemistry

DIPartimento per lo studio della TErra e delle sue RISorse -  
Università  di Genova
Tel. ++39 010 3538136 Fax. ++39 010 352169
Corso Europa 26, 16132 - Genova - Italy