<div dir="ltr">Dear Sathya,<br><br>I have no experience in using 'vc-relax'.......so I can't help you out on this. Either you wait for other people's comments or you can search the pw forum mailing list. There were discussions regarding this earlier in this forum. I said its tricky because you need to choose different parameters correctly to reach the minima quickly and correctly. What I would suggest is to play around with different parameters for some small system and understand how they affects the calculation. Later you can go for production run.<br>
<br>Prasenjit.<br><br><div class="gmail_quote">2008/7/30 sathya subramanyan <span dir="ltr"><<a href="mailto:sathya_sheela1985001@rediffmail.com">sathya_sheela1985001@rediffmail.com</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<p>
<br>
Dear Dr. Prasenjit,<br>
Thank you so much for your reply and the link.<br>
I'm doing the vc-relax calculation but it has been running for more than 36 hours.Is this why you have mentioned that vc-relax is tricky ? I have attached the I/P file for reference and if you could please take a look at it.<br>
I'm also trying the manual relaxation and will let you know the status of my results.<br>
<br>
INPUT FILE FOR VC-RELAX<br>
<br>
&CONTROL<br>
calculation = "vc-relax" ,<br>
restart_mode = 'from_scratch' ,<br>
outdir='/home/413107002/tmp/' ,<br>
pseudo_dir = '/home/413107002/espresso-4.0.1/pseudo' ,<br>
nstep = 1000 ,<br>
etot_conv_thr = 1.0E-10 ,<br>
forc_conv_thr = 1.0D-10 ,<br>
dt = 150 ,<br>
/<br>
&SYSTEM<br>
ibrav = 6 ,<br>
celldm(1)=7.373 ,<br>
celldm(3)=1.065,<br>
nat = 5 , <br>
ntyp = 3 , <br>
ecutwfc = 30.0,<br>
ecutrho = 300.0 , <br>
occupations = 'fixed' ,<br>
degauss = 0.00 , <br>
/<br>
&ELECTRONS <br>
conv_thr = 1.0d-10 , <br>
diagonalization = 'david' , <br>
/<br>
&IONS<br>
ion_dynamics = 'damp'<br>
/<br>
&CELL<br>
cell_dynamics = 'damp-w' ,<br>
<br>
/<br>
ATOMIC_SPECIES<br>
Pb 207.2 Pb.vdb.UPF<br>
Ti 47.867 Ti.vdb.UPF<br>
O 15.9994 O.vdb.UPF<br>
ATOMIC_POSITIONS <br>
Pb 0.000 0.000 0.000<br>
Ti 0.500 0.500 0.538<br>
O 0.500 0.000 0.612<br>
O 0.000 0.500 0.612<br>
O 0.500 0.500 0.117<br>
K_POINTS {automatic} <br>
4 4 4 1 1 1 <br>
<br>
Thanking you,
</p>
SATHYA SHEELA.S
<br>
Grad. Student
<br>
Department of Physics
<br>
National Institute of Technology
<br>
Tiruchirapalli - 620015
<br>
India<br><br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>PRASENJIT GHOSH,<br>POST-DOC,<br>ROOM NO: 265, MAIN BUILDING,<br>CM SECTION, ICTP,<br>STRADA COSTERIA 11,<br>TRIESTE, 34104,<br>ITALY<br>PHONE: +39 040 2240 369 (O)<br>
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