[Pw_forum] relax problem

Ben Hope bth20 at cam.ac.uk
Fri Feb 4 11:41:06 CET 2005

```Hi

I am performing a relax calculation on a very thin Cobalt cylinder. The
relaxation process converges if it is non spin-polarized (nspin=1) but not
if it is spin-polarized (nspin=2). I have tried reducing the mixing beta but
it didn't help.

Any ideas?

Here is the input file:

&CONTROL

calculation = 'relax' ,

restart_mode = 'from_scratch' ,

pseudo_dir = '/scratch/bth/Programs/Espresso/pseudo/' ,

prefix = 'CoCyl01',

verbosity = 'high',

/

&SYSTEM

ibrav = 8,

celldm(1) = 4.0695,

celldm(2) = 6.0,

celldm(3) = 6.0,

nat = 10,

ntyp = 1,

ecutwfc = 30 ,

ecutrho = 80 ,

occupations = 'smearing',

degauss = 0.03,

nspin = 2,

starting_magnetization(1) = 1.0,

/

&ELECTRONS

mixing_beta = 0.5

conv_thr =  1.0d-7

/

&IONS

upscale = 10,

/

&CELL

/

ATOMIC_SPECIES

Co   58.93  Co.pbe-nd-rrkjus.UPF

ATOMIC_POSITIONS {crystal}

Co      0.0  0.0  0.0  1  1  1

Co      0.0  0.1026784617  0.0  1  1  1

Co      0.0  -0.1026784617  0.0  1  1  1

Co      0.0  0.0513392309  0.0889221563  1  1  1

Co      0.0  -0.0513392309  0.0889221563  1  1  1

Co      0.0  0.0513392309  -0.0889221563  1  1  1

Co      0.0  -0.0513392309  -0.0889221563  1  1  1

Co      0.5  0.0513392309  0.0296407188  1  1  1

Co      0.5  -0.0513392309  0.0296407188  1  1  1

Co      0.5  0.0  -0.0592814375  1  1  1

K_POINTS {automatic}

7 1 1   1 1 1

====================================
Ben Hope
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St. John's College
CAMBRIDGE
CB2 1TP

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```