[Pw_forum] Run using a relaxed structure as initial one NOT converge in fir st few ionic steps.
quantum
quantum at mail.ncyu.edu.tw
Tue Dec 20 11:05:02 CET 2016
Dear Giovanni and Stefano:
Thank you very much for your response.
Listed below are the details of input and output.
----- The first input file --------------------------------------
&control
title = 'Gypsum (CaSO4.2H20 Z=4)'
prefix = 'gyp-pbe-mt_fhi-exp1.01G-opt'
outdir = '/work2/u2equa02/tempdir/gyp-pbe-mt_fhi-exp1.01G-opt'
pseudo_dir = '/home/u2equa02/quantumhome/pseudo'
calculation = 'relax'
restart_mode = 'from_scratch'
disk_io = 'low'
verbosity = 'high'
wf_collect = .true.
tstress = .true.
tprnfor = .true.
etot_conv_thr = 1.0D-4
forc_conv_thr = 1.0D-3
max_seconds = 466560
/
&system
space_group = 15
uniqueb = .true.
origin_choice = 1
celldm(1) = 11.79378074341055 ! bohr
celldm(2) = 2.42429097900977
celldm(3) = 0.904502483576350
celldm(5) = -0.413422293216829
ntyp = 4
nat = 7
ecutwfc = 240
ecutrho = 960
vdw_corr = 'grimme-d2'
/
&electrons
electron_maxstep = 200
conv_thr = 1.0D-6
startingpot = 'atomic'
startingwfc = 'atomic+random'
mixing_mode = 'plain'
mixing_beta = 0.5
mixing_ndim= 8
diagonalization = 'david'
/
&ions
ion_dynamics = 'bfgs'
/
ATOMIC_SPECIES
Ca 40.0780000000 Ca.pbe-mt_fhi.UPF
S 32.0650000000 S.pbe-mt_fhi.UPF
O 15.9994000000 O.pbe-mt_fhi.UPF
H 1.0079000000 H.pbe-mt_fhi.UPF
ATOMIC_POSITIONS crystal_sg
Ca 0.00000 0.16960 0.25000
S 0.00000 0.32680 0.75000
O 0.08400 0.27200 0.59000
O 0.20000 0.38200 0.91500
O -0.21300 0.06300 -0.08000
H -0.25800 0.08700 -0.23400
H -0.24400 0.02000 -0.07700
K_POINTS automatic
12 12 12 0 0 0
----------------------------------------------
The last section of "ATOMIC_POSITIONS (crystal)" ----------------
ATOMIC_POSITIONS (crystal)
Ca 0.831507586 0.168492414 0.250000000
Ca 0.168492414 0.831507586 0.750000000
S 0.670838834 0.329161166 0.750000000
S 0.329161166 0.670838834 0.250000000
O 0.814789681 0.361192199 0.593221086
O 0.638807801 0.185210319 0.906778914
O 0.185210319 0.638807801 0.406778914
O 0.361192199 0.814789681 0.093221086
O 0.817560716 0.587016680 0.921747159
O 0.412983320 0.182439284 0.578252841
O 0.182439284 0.412983320 0.078252841
O 0.587016680 0.817560716 0.421747159
O 0.713851138 0.844837552 0.919788047
O 0.155162448 0.286148862 0.580211953
O 0.286148862 0.155162448 0.080211953
O 0.844837552 0.713851138 0.419788047
H 0.650318830 0.820912679 0.741084444
H 0.179087321 0.349681170 0.758915556
H 0.349681170 0.179087321 0.258915556
H 0.820912679 0.650318830 0.241084444
H 0.749428151 0.753450611 0.911642228
H 0.246549389 0.250571849 0.588357772
H 0.250571849 0.246549389 0.088357772
H 0.753450611 0.749428151 0.411642228
----------------------------------------------------------------
I understand, when using space_group to specify atomic positions
a conversion between coordinates of convectional and centered cells
is performed. (Thanks to Andrea Dal Corso)
So, I manually reverted the conversion, following the PW code below.
============================================================
espresso-5.3.0/PW/src/wyckoff.f90:
SUBROUTINE ccord(outco,sym_n,not_eq,ibrav,unique)
CASE (-13) !Centrato B unique MONOCLINO
DO k=1,not_eq
DO i=1,sym_n
tmpx=outco(1,i,k)
tmpy=outco(2,i,k)
outco(1,i,k)=tmpx-tmpy
outco(2,i,k)=tmpy+tmpx
END DO
END DO
===========================================================
After manually reverting the above process, I identify the positions of the 7 inequivelent atoms, and use them for the new run.
The new input file --------------------------------------------------------
&control
title = 'Gypsum (CaSO4.2H20 Z=4)'
prefix = 'gyp-pbe-mt_fhi-exp1.01G-opt-cont'
outdir = '/work2/u2equa02/tempdir/gyp-pbe-mt_fhi-exp1.01G-opt-cont'
pseudo_dir = '/home/u2equa02/quantumhome/pseudo'
calculation = 'relax'
restart_mode = 'from_scratch'
disk_io = 'low'
verbosity = 'high'
wf_collect = .true.
tstress = .true.
tprnfor = .true.
etot_conv_thr = 1.0D-4
forc_conv_thr = 1.0D-3
/
&system
space_group = 15
uniqueb = .true.
origin_choice = 1
celldm(1) = 11.79378074341055 ! bohr
celldm(2) = 2.42429097900977
celldm(3) = 0.904502483576350
celldm(5) = -0.413422293216829
ntyp = 4
nat = 7
ecutwfc = 240
ecutrho = 960
vdw_corr = 'grimme-d2'
/
&electrons
electron_maxstep = 200
conv_thr = 1.0D-6
startingpot = 'atomic'
startingwfc = 'atomic+random'
mixing_mode = 'plain'
mixing_beta = 0.5
mixing_ndim= 8
diagonalization = 'david'
/
&ions
ion_dynamics = 'bfgs'
/
ATOMIC_SPECIES
Ca 40.0780000000 Ca.pbe-mt_fhi.UPF
S 32.0650000000 S.pbe-mt_fhi.UPF
O 15.9994000000 O.pbe-mt_fhi.UPF
H 1.0079000000 H.pbe-mt_fhi.UPF
ATOMIC_POSITIONS crystal_sg
Ca 0.000000000 0.168492414 0.250000000
S 0.000000000 0.329161166 0.750000000
O 0.087990940 0.273201259 0.593221086
O 0.202288698 0.384727982 0.921747159
O -0.220655655 0.065493207 -0.080211953
H -0.264384246 0.085296924 -0.258915556
H -0.248560619 0.002011230 -0.088357772
K_POINTS automatic
12 12 12 0 0 0
------------------------------------------------------------
The new run does not converge after an ionic step.
Sincerely,
Tsung-Lung Li
-----Original message-----
From:stefano de gironcoli <degironc at sissa.it>
To:pw_forum at pwscf.org
Date:Tue, 20 Dec 2016 17:34:17
Subject:Re: [Pw_forum] Run using a relaxed structure as initial one NOT converge in fir st few ionic steps.
dear Tsung-Lung Li,
Your expectations are correct.
If this is what you experience you probably are not doing what you think
you are doing but it is difficult to make any suggestion without further
information
stefano
On 20/12/2016 10:26, quantum wrote:
> Dear QE Friends:
>
> I did a "relax" calculation with PW (version 5.3.0)
> and obtained the relaxed atomic positions.
>
> Then, I took the atomic positions
> in the last "ATOMIC_POSITIONS (crystal)"
> section of the output file to replace the
> atomic positions in the original input file
> without changing any other things except new
> prefix and outdir.
>
> The atoms in the relaxed structure should
> all satisfy etot_conv_thr and forc_conv_thr
> thresholds. With this in mind, I started
> the new run.
>
> I expected the run to
> converge after the first or two ionic steps.
> But it did not stop, and continued running
> for many ionic steps without convergence.
>
> Is my expectation correct? or it is a problem
> of QE?
>
> Sincerely,
> Tsung-Lung Li
>
>
> Tsung-Lung Li, Ph. D.
> Professor
> Department of Applied Physics
> National Chia-Yi University
> 300 Hsueh-Fu Road, Chiayi 60004, Taiwan
> Phone: 886-5-2717904. FAX: 886-5-2717909.
> E-mail:quantum at mail.ncyu.edu.tw
> URL:http://web.ncyu.edu.tw/~quantum
>
> _______________________________________________
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Tsung-Lung Li, Ph. D.
Professor
Department of Applied Physics
National Chia-Yi University
300 Hsueh-Fu Road, Chiayi 60004, Taiwan
Phone: 886-5-2717904. FAX: 886-5-2717909.
E-mail:quantum at mail.ncyu.edu.tw
URL:http://web.ncyu.edu.tw/~quantum
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