[Pw_forum] Oscillation behavior for structure optimization
ruizhi zhang
rui_zhi_zhang at yahoo.com
Tue Mar 27 05:22:32 CEST 2007
hi okuno
I can not slove your problem because I am a beginer as you are. But I have another way to get a monoclinic phase PZT. The input&outfile are attached below. By the way, I do not think it is correct to fix z-coordinate, because you perhaps will not get a 'groud state'.
Hope this helps
Best regards
ruizhi
INPUT:
&control
calculation = 'relax'
restart_mode = 'from_scratch'
prefix = 'pzt.mono.rl'
pseudo_dir = '/'
outdir = '/'
/
&system
ibrav=0
celldm(1)=7.73
nat=20
ntyp=4
ecutwfc=30.0
occupations = 'fixed'
/
&electrons
conv_thr = 1e-8,
mixing_beta=0.3,
/
&IONS
/
ATOMIC_SPECIES
Pb 207.2 Pb.vdb.UPF
Ti 47.867 Ti.vdb.UPF
Zr 91.22 Zr.vdb.UPF
O 15.9994 O.vdb.UPF
ATOMIC_POSITIONS
Pb 0.0 0.0 0.0
Zr 0.485 0.485 0.47
O 0.0 0.5 0.5
O 0.5 0.0 0.5
O 0.5 0.5 0.0
Pb 0.0 1.0 0.0
Ti 0.485 1.485 0.47
O 0.0 1.5 0.5
O 0.5 1.0 0.5
O 0.5 1.5 0.0
Pb 0.0 0.0 1.0
Ti 0.485 0.485 1.47
O 0.0 0.5 1.5
O 0.5 0.0 1.5
O 0.5 0.5 1.0
Pb 0.0 1.0 1.0
Zr 0.485 1.485 1.47
O 0.0 1.5 1.5
O 0.5 1.0 1.5
O 0.5 1.5 1.0
K_POINTS {automatic}
4 2 2 0 0 0
CELL_PARAMETERS
1 0 0
0 2 0
0 0 2
OUTPUT,this is a monoclinic phase PZT
ATOMIC_POSITIONS (alat)
Pb -0.074746117 -0.054391084 -0.052737416
Zr 0.475968064 0.476554616 0.469572490
O -0.002812771 0.540060157 0.546351440
O 0.538456743 -0.005360148 0.524405291
O 0.538229142 0.529414476 -0.011303199
Pb -0.060631754 0.929474660 -0.080635128
Ti 0.461835759 1.468464184 0.467563250
O 0.029392570 1.525039365 0.520132029
O 0.532671091 1.026126063 0.530617774
O 0.531637274 1.534617711 0.026033468
Pb -0.060631754 -0.070525340 0.919364872
Ti 0.461835759 0.468464184 1.467563250
O 0.029392570 0.525039365 1.520132029
O 0.532671091 0.026126063 1.530617774
O 0.531637274 0.534617711 1.026033468
Pb -0.074746117 0.945608916 0.947262584
Zr 0.475968064 1.476554616 1.469572490
O -0.002812771 1.540060157 1.546351440
O 0.538456743 0.994639852 1.524405291
O 0.538229142 1.529414476 0.988696801
yukihiro_okuno at fujifilm.co.jp wrote:
Dear PWscf Users.
I'm now calculating the structure optimization for
monoclinic structure of PZT ( put a little shere stress for
tetragonal structure).
But the calculation is not conversed and the Total force
is oscillate like below, and this does not happen for tetragonal case.)
Total force = 0.029288 Total SCF correction = 0.000028
Total force = 0.610879 Total SCF correction = 0.000006
Total force = 0.031826 Total SCF correction = 0.000017
Total force = 0.017717 Total SCF correction = 0.000010
Total force = 0.006548 Total SCF correction = 0.000009
Total force = 0.004523 Total SCF correction = 0.000024
Total force = 0.002241 Total SCF correction = 0.000004
Total force = 0.001565 Total SCF correction = 0.000008
Total force = 0.001102 Total SCF correction = 0.000005
Total force = 0.001312 Total SCF correction = 0.000010
Total force = 0.001605 Total SCF correction = 0.000009
Total force = 0.001865 Total SCF correction = 0.000006
Total force = 0.002391 Total SCF correction = 0.000005
Total force = 0.002574 Total SCF correction = 0.000005
Total force = 0.001872 Total SCF correction = 0.000008
Total force = 0.001495 Total SCF correction = 0.000006
Total force = 0.001430 Total SCF correction = 0.000005
Total force = 0.001529 Total SCF correction = 0.000003
Total force = 0.001736 Total SCF correction = 0.000004
Total force = 0.002315 Total SCF correction = 0.000004
Total force = 0.002271 Total SCF correction = 0.000008
Total force = 0.001826 Total SCF correction = 0.000008
Total force = 0.001623 Total SCF correction = 0.000004
Total force = 0.001605 Total SCF correction = 0.000007
Total force = 0.001720 Total SCF correction = 0.000006
Total force = 0.002129 Total SCF correction = 0.000003
Total force = 0.002290 Total SCF correction = 0.000007
Total force = 0.002437 Total SCF correction = 0.000006
Total force = 0.002619 Total SCF correction = 0.000006
Total force = 0.002860 Total SCF correction = 0.000007
Total force = 0.003199 Total SCF correction = 0.000006
Total force = 0.003772 Total SCF correction = 0.000006
My input file is like below and how should we treat such a trouble?
&control
calculation = 'relax',
restart_mode = 'from_scratch',
pseudo_dir = '/home/okuno/PWSCF/espresso-3.2/pseudo/',
outdir = './',
prefix='PZT'
forc_conv_thr = 1.0D-4
/
&system
ibrav=12
celldm(1)=7.57696068724
celldm(2)=2.09
celldm(3)=1.00
celldm(4)=0.00499993750117
nat=10
ntyp=4
nbnd=44
ecutwfc=60.0
ecutrho = 600.0
occupations = 'fixed'
degauss=0.00
/
&electrons
conv_thr = 1e-10,
mixing_beta=0.3,
/
&IONS
ion_dynamics='bfgs'
bfgs_ndim=3
pot_extrapolation = "second_order"
wfc_extrapolation = "second_order"
trust_radius_min=1.0D-4
/
ATOMIC_SPECIES
Pb 207.2 pb_ps.uspp.UPF
Zr 91.224 zr_ps.uspp.UPF
Ti 47.867 ti_ps.uspp.UPF
O 15.9994 o_ps.uspp.UPF
ATOMIC_POSITIONS {crystal}
Pb 0.0 0.00000 0.0 1 1 0
Pb 0.0 0.53106 0.0 1 1 0
Zr 0.5 0.24462 0.5 1 1 0
Ti 0.5 0.74062 0.5 1 1 0
O 0.5 0.95432 0.5 1 1 0
O 0.5 0.48072 0.5 1 1 0
O 0.5 0.19090 0.0 1 1 0
O 0.0 0.19090 0.5 1 1 0
O 0.5 0.71336 0.0 1 1 0
O 0.0 0.71336 0.5 1 1 0
K_POINTS {automatic}
6 6 6 0 0 0
,
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