<div dir="ltr"><div><div><div><div>Dear A. P. Seitsonen,<br><br></div>thank you for your suggestions. I will try it. Would you please explain more about your comment "Please try multiplying your lattice vectors laterally by two". What is motivation behind this move ? The input lattice vectors are in accordance with the 2*2 supercell. <br><br></div>Best wishes<br></div>Masood Yousaf<br></div>UNIST, KOREA <br><div><div><div><div><div><br><br></div></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Oct 8, 2015 at 5:30 PM, Ari P Seitsonen <span dir="ltr"><<a href="mailto:Ari.P.Seitsonen@iki.fi" target="_blank">Ari.P.Seitsonen@iki.fi</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Dear Masood Yousaf,<br>
<br>
Please try multiplying your lattice vectors laterally by two; I would also try the 'mixing_mode = "local-TF"': That works better for me in inhomogeneous systems such as slabs (ie where there are high-density regions and vacuum).<br>
<br>
Some other notes:<br>
<br>
- Why not using 'ibrav = 4' and 'a', 'c' to define the lattice vectors? You would have much better accuracy, symmetries etc. Likewise for the coordinates, more precise digits would allow finding symmetries etc<br>
<br>
- Eventually the FHI potentials will need much higher cut-off energy, I seem to remember something like 90-120 Ry for Ni... (just for curiosity, I had the honour to share the office for some time with the GPP, Guru of Pseudo Potentials, at FHI, from whom the parametres of these pseudos might still originate from ;)<br>
<br>
Good Luck from Almost-Sunny Montrouge,<br>
<br>
apsi<br>
<br>
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-<br>
Ari Paavo Seitsonen / <a href="mailto:Ari.P.Seitsonen@iki.fi" target="_blank">Ari.P.Seitsonen@iki.fi</a> / <a href="http://www.iki.fi/~apsi/" rel="noreferrer" target="_blank">http://www.iki.fi/~apsi/</a><br>
Ecole Normale Supérieure (ENS), Département de Chimie, Paris<br>
Mobile (F) : <a href="tel:%2B33%20789%2037%2024%2025" value="+33789372425" target="_blank">+33 789 37 24 25</a> (CH) : <a href="tel:%2B41%2079%2071%2090%20935" value="+41797190935" target="_blank">+41 79 71 90 935</a><br>
<br>
<br>
On Thu, 8 Oct 2015, Masood Yousaf wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear Members,<br>
<br>
Kindly have a look at the input file and suggest why its so hard to<br>
converge this relatively moderate system. I tried to fix in different ways<br>
but failed. I tried the same structure in VASP and had no problem. I want to<br>
calculate RAMMAN spectra and that can only be calculated with LDA functional<br>
in Quantum espresso. I am using QE 5.1.<br>
<br>
<br>
&control<br>
calculation='relax'<br>
restart_mode='from_scratch'<br>
pseudo_dir = '/share/QE_pseudo'<br>
outdir='./'<br>
prefix='Graphane'<br>
forc_conv_thr=1.0D-4<br>
nstep=10000<br>
/<br>
&system<br>
ibrav= 0<br>
nat= 32, ntyp= 3<br>
nspin =2<br>
starting_magnetization(2) = 0.7<br>
ecutwfc =60.0<br>
occupations='smearing'<br>
degauss=0.002<br>
smearing='mv',<br>
/<br>
&electrons<br>
conv_thr=1.0D-9<br>
mixing_mode='plain'<br>
mixing_beta=0.1D0<br>
/<br>
&ions<br>
ion_dynamics = 'bfgs'<br>
/<br>
! &cell<br>
! cell_dynamics = 'damp-w'<br>
! cell_factor = 10.1D0<br>
/<br>
CELL_PARAMETERS {angstrom}<br>
4.9363447999999996 0.0000000000000000 0.0000000000000000<br>
2.4681723999999998 4.2750000000000004 0.0000000000000000<br>
0.0000000000000000 0.0000000000000000 25.0000000000000000<br>
ATOMIC_SPECIES<br>
C 12.0111 C.pw-mt_fhi.UPF<br>
Ni 58.6934 Ni.pw-mt_fhi.UPF<br>
F 18.9984 F.pw-mt_fhi.UPF<br>
ATOMIC_POSITIONS {angstrom}<br>
C 3.116840000 3.174350000 1.386070000<br>
C 5.584900000 3.174230000 1.386000000<br>
C 1.882610000 1.036880000 1.385940000<br>
C 4.350760000 1.036680000 1.385960000<br>
C 1.882750000 2.461910000 1.888240000<br>
C <a href="tel:0.648640000" value="+92648640000" target="_blank">0.648640000</a> 0.324320000 1.888230000<br>
C 4.350960000 2.461770000 1.888140000<br>
C 3.116790000 0.324280000 1.888150000<br>
C 1.882980000 2.461940000 3.476540000<br>
C <a href="tel:0.648890000" value="+92648890000" target="_blank">0.648890000</a> 0.324350000 3.476400000<br>
C 4.351250000 2.461930000 3.476230000<br>
C 3.117130000 0.324400000 3.476380000<br>
C 6.819130000 3.887150000 3.951040000<br>
C 4.351050000 3.887040000 3.950790000<br>
C 3.116960000 1.749700000 3.950740000<br>
C 5.585010000 1.749700000 3.950910000<br>
Ni 6.828000000 3.886970000 5.917170000<br>
Ni 3.131720000 0.323340000 7.993850000<br>
Ni 4.367640000 1.035220000 10.009150000<br>
Ni 4.359850000 3.886850000 5.916790000<br>
Ni <a href="tel:0.663590000" value="+92663590000" target="_blank">0.663590000</a> 0.323340000 7.993930000<br>
Ni 1.899450000 1.035270000 10.009360000<br>
Ni 5.593900000 1.749490000 5.916940000<br>
Ni 4.365770000 2.460850000 7.993890000<br>
Ni 5.601750000 3.172800000 10.009260000<br>
Ni 3.125750000 1.749380000 5.916700000<br>
Ni 1.897660000 2.460880000 7.993900000<br>
Ni 3.133520000 3.172820000 10.009440000<br>
F 5.584240000 3.175000000 0.000730000<br>
F 4.350170000 1.037440000 0.000850000<br>
F 1.882110000 1.037660000 0.000890000<br>
F 3.116200000 3.175230000 0.000920000<br>
K_POINTS {automatic}<br>
5 5 1 0 0 0<br>
<br><span class="HOEnZb"><font color="#888888">
<br>
--<br>
<br>
Best Wishes<br>
<br>
Masood Yousaf<br>
<br>
Ulsan National Institute of Science and Technology, Korea<br>
<br>
<br>
<br>
</font></span></blockquote>
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<p style="margin:0in 0in 0.0001pt;text-align:justify"><span style="font-family:times new roman,serif"><span lang="EN-GB">Postdoctoral researcher</span></span></p>
<p style="margin:0in 0in 0.0001pt;text-align:justify"><span style="font-family:times new roman,serif"><span lang="EN-GB">Ulsan National Institute of Science and Technology, Korea</span></span></p><p style="margin:0in 0in 0.0001pt;text-align:justify"><span style="font-family:times new roman,serif">Cell.: <a href="tel:%2B82-10-4452-0850" value="+821044520850" target="_blank">+82-010-3320-1984</a></span></p></div></div></div></div></div></div>
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