[Pw_forum] Problem with vc -relax

[shruba at gmail.com]

Hi all,
     I was trying to run vc-relax calculation for srfeo3 ( antiferromagnetic
mettalic ) system,  the problem I was facing for a unit cell it is running
for 3-4 days in processor , where as a single point 'scf' calculation is
taking only 5 minutes, the scf calculation is giving very nice agreement
with experimental data , but for vc -relax  i checked the cell volume was
decresing first then it started exapnding after a certain point, this is my
input file . If any one can help me in this matter that will be really great
help, I am using same cutoff and other parameters required for scf

&CONTROL

calculation = 'vc-relax',

restart_mode = 'from_scratch',

tstress = .TRUE.,

tprnfor = .TRUE.,

prefix = 'relax',

pseudo_dir = '/............./',

outdir='/................../'

/

&SYSTEM

ibrav = 1,

celldm(1) = 7.3

nat =5,

ntyp =3,

ecutwfc = 45,

ecutrho = 360,

nspin=2,

nelec=44

nelup=26,

neldw=18,

nbnd=52,

occupations = 'smearing',

smearing ='marzari-vanderbilt',

degauss=0.03,

qcutz=150., q2sigma=2.0,ecfixed=10.0

/

&ELECTRONS

electron_maxstep =200,

emass =1000.d0,

emass_cutoff = 4.d0,

orthogonalization = 'Gram-Schmidt',

startingwfc ='atomic',

n_inner = 8,

tcg = .TRUE.,

passop=0.3,

maxiter = 250,

conv_thr=1.d-6,

/

&IONS

ion_dynamics = 'damp',

ion_damping = 0.,

ion_positions = 'from_input',

ion_temperature = 'not_controlled',

/

&CELL

cell_dynamics = 'damp-w'

/

ATOMIC_SPECIES

Fe 55.85 Fe.pbe-sp-van.UPF

Sr 87.62 Sr.pbe-nsp-van.UPF

O 16.00 O.pbe-van-bm.UPF

ATOMIC_POSITIONS

Sr 0.000 0.000 0.010

Fe 0.500 0.500 0.500

O 0.000 0.500 0.500

O 0.500 0.500 0.000

O 0.500 0.000 0.500

K_POINTS {automatic}

8 8 8 1 1 1

Thanks in advance , looking forward for your reply
                                shruba

-- 
shruba gangopadhyay
graduate student
department of chemistry
university of central florida
orlando, FL-32826
'friendship doubles joys and reduces sorrows by half' (Francis Bacon).
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