[Pw_forum] roblem with bfgs algorithm optimizer for spin polarized system

Giuseppe Mattioli giuseppe.mattioli at mlib.ism.cnr.it
Fri Mar 13 17:16:22 CET 2009


> If I were you, I would try without the "cell_dofree" option, which has not
> been maintained in awhile, to the point I'm not sure it is working as it
> should, especially for BFGS.

I may have missed it, but if not I suggest including a comprehensive example 
regarding the use of different vc-relax schemes within the next QE 
distribution...
However I used recently the bfgs (both on the ions and on the cell parameters)
method and the cell_dofree option without problems. I still suspect that 
Piero's problem concerns some "electronic" stuff. 

export FILE="anat12-vcr-bfgs"
export INPFILE=$FILE-2.inp
export OUTFILE=$FILE-2.out
echo " $FILE"
echo " $INPFILE"
echo " $OUTFILE"

cat > $INPFILE << EOF
 &control
    calculation = 'vc-relax'
    restart_mode='restart',
    prefix='$FILE',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/',
    tstress=.true.,
    tprnfor=.true.,
    nstep=200,
    etot_conv_thr=1.0E-5,
    forc_conv_thr=1.0D-4,
 /
 &system
    ibrav=6, celldm(1)=7.15262, celldm(3)=2.51360,
    nat=12, ntyp=2,
    ecutwfc=25.0,
    ecutrho=150.,
    occupations='smearing', degauss=0.01,
    nspin=1,
 /
 &electrons
    mixing_mode='plain'
    mixing_beta=0.3
    conv_thr=1.0d-9
    electron_maxstep=200
 /
 &ions
    ion_dynamics='bfgs'
 /
 &cell
    cell_dynamics='bfgs',
    press =0.00,
    cell_dofree='xyz',
 /
ATOMIC_SPECIES
Ti   47.900     Ti12_pbe.van.UPF
O    15.999     O_pbe.van.UPF
ATOMIC_POSITIONS {crystal}
Ti   0.0000  0.0000  0.0000
Ti   0.0000  0.5000  0.2500
Ti   0.5000  0.5000  0.5000
Ti   0.5000  1.0000  0.7500
 O   0.0000  0.0000  0.2066
 O   0.0000  0.0000 -0.2066
 O   0.0000  0.5000  0.4566
 O   0.0000  0.5000  0.0434
 O   0.5000  0.5000  0.7066
 O   0.5000  0.5000  0.2934
 O   0.5000  1.0000  0.9566
 O   0.5000  1.0000  0.5434
K_POINTS {automatic}
4, 4, 2, 0, 0, 0
EOF
$PARA_PREFIX $ESPRESSO/pw.x $PARA_POSTFIX < $INPFILE >> $OUTFILE


On Friday 13 March 2009 15:09:42 Lorenzo Paulatto wrote:
> On Fri, 13 Mar 2009 15:07:22 +0100, <pc229 at kent.ac.uk> wrote:
> > Thanks for the reply,
> > buT I am still thinking that should be a bug in the optimizer, since  I
> > also tried to run my system like a metal and nothing gonna change.
>
>
> cheers

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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
   v. Salaria Km 29,300 - C.P. 10                
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