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<DIV><FONT face=宋体 size=2>However, now there are many abinit packages based
plane-waves which don't use disk but RAM to store wavefunctions, meaning it
could be at least as a option. </FONT><FONT face=宋体 size=2>Otherwise, such an
often writing on disk not only wastes too much time, but also leads to NFS
crashing, even for a small system. Each wavefunction files for a job
with e.g. 50 atoms for 16 nodes is not more than 200M, it could be
</FONT><FONT face=宋体 size=2>run in a PC-Cluster with a standard
configuration of 1G/CPU, no problem. However, two these jobs running leads
to NFS very slow or crashing, since every ten-seconds it needs to write 6G
data on disk. </FONT></DIV>
<DIV><FONT face=宋体 size=2></FONT> </DIV>
<DIV><FONT face=宋体 size=2>JG</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 9pt 宋体">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 9pt 宋体; font-color: black"><B>From:</B>
<A title=baroni@sissa.it href="mailto:baroni@sissa.it">Stefano Baroni</A>
</DIV>
<DIV style="FONT: 9pt 宋体"><B>To:</B> <A title=pw_forum@pwscf.org
href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</A> </DIV>
<DIV style="FONT: 9pt 宋体"><B>Sent:</B> Tuesday, April 04, 2006 1:43 PM</DIV>
<DIV style="FONT: 9pt 宋体"><B>Subject:</B> Re: [Pw_forum] about output
wavefunction, charge density and potential</DIV>
<DIV><BR></DIV><BR>
<DIV>
<DIV>On Apr 4, 2006, at 3:02 AM, J G Che wrote:</DIV><BR
class=Apple-interchange-newline>
<BLOCKQUOTE type="cite">
<DIV style="MARGIN: 0px">Dear Paolo:</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Thanks for you replying.<SPAN
class=Apple-converted-space> </SPAN></DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Do you mean that pwscf uses disk to store
wavefunctions?<SPAN class=Apple-converted-space> </SPAN></DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">I think it is not necessary to store wavefunction
on disk, since now the RAM is very sheap.<SPAN
class=Apple-converted-space> </SPAN></DIV></BLOCKQUOTE>
<DIV><BR class=khtml-block-placeholder></DIV>well, this statement is, strictly
speaking, not much meaningful until one specifies </DIV>
<DIV><BR class=khtml-block-placeholder></DIV>
<DIV>1) how greedy one is and </DIV>
<DIV>2) how large is one's wallet ...</DIV>
<DIV><BR class=khtml-block-placeholder></DIV>
<DIV>SB</DIV>
<DIV><BR>
<BLOCKQUOTE type="cite">
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Che</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">----- Original Message -----<SPAN
class=Apple-converted-space> </SPAN></DIV>
<DIV style="MARGIN: 0px">From: "Paolo Giannozzi" <<A
href="mailto:giannozz@nest.sns.it">giannozz@nest.sns.it</A>></DIV>
<DIV style="MARGIN: 0px">To: <<A
href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</A>></DIV>
<DIV style="MARGIN: 0px">Sent: Tuesday, April 04, 2006 2:55 AM</DIV>
<DIV style="MARGIN: 0px">Subject: Re: [Pw_forum] about output wavefunction,
charge density and potential</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV style="MARGIN: 0px">On Saturday 01 April 2006 05:10, J G Che
wrote:</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV style="MARGIN: 0px">I find that in each iterative, wavefunction,
potential and charge density</DIV>
<DIV style="MARGIN: 0px">will be saved on disk. Who knows how to output
these once only when<SPAN
class=Apple-converted-space> </SPAN></DIV>
<DIV style="MARGIN: 0px">the self-consistent is reached.
Thanks!</DIV></BLOCKQUOTE>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">- if you have more than one k-point per
processor, you have to save</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>wavefunctions to disk. It would be possible to store them into
memory<SPAN class=Apple-converted-space> </SPAN></DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>but it would require extensive changes to the code (and a lot of
memory)</DIV>
<DIV style="MARGIN: 0px">- if you have just one k-point and do not specify
disk_io='high' the</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>code will write wavefunctions only at convergence</DIV>
<DIV style="MARGIN: 0px">- the charge density and potential are written at
each scf step.</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>This is a behavior that could be changed with simple
modifications</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>in the code. These arrays however are usually much smaller
than</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>the wavefunctions.</DIV>
<DIV style="MARGIN: 0px">- unless you specify disk_io='high', auxiliary
arrays used for</DIV>
<DIV style="MARGIN: 0px"><SPAN class=Apple-converted-space>
</SPAN>self-consistency are not written to disk but stored</DIV>
<DIV style="MARGIN: 0px">- other files are typically small</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Paolo</DIV>
<DIV style="MARGIN: 0px">--<SPAN
class=Apple-converted-space> </SPAN></DIV>
<DIV style="MARGIN: 0px">Paolo Giannozzi <SPAN
class=Apple-converted-space>
</SPAN>e-mail:<SPAN class=Apple-converted-space> </SPAN><A
href="mailto:giannozz@nest.sns.it">giannozz@nest.sns.it</A></DIV>
<DIV style="MARGIN: 0px">Scuola Normale Superiore<SPAN
class=Apple-converted-space> </SPAN>Phone: <SPAN
class=Apple-converted-space> </SPAN>+39/050-509876, Fax:-563513<SPAN
class=Apple-converted-space> </SPAN></DIV>
<DIV style="MARGIN: 0px">Piazza dei Cavalieri 7<SPAN
class=Apple-converted-space> </SPAN>I-56126 Pisa,
Italy</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV
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<DIV style="MARGIN: 0px"><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">---</SPAN></SPAN></SPAN></FONT></DIV>
<DIV style="MARGIN: 0px"><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">Stefano Baroni -
SISSA</SPAN></SPAN></SPAN></FONT><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"> </SPAN></SPAN></SPAN></FONT><FONT
class=Apple-style-span size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">&</SPAN></SPAN></SPAN></FONT><FONT
class=Apple-style-span size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"> </SPAN></SPAN></SPAN></FONT><FONT
class=Apple-style-span size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">DEMOCRITOS National Simulation Center -
Trieste</SPAN></SPAN></SPAN></FONT></DIV>
<DIV style="MARGIN: 0px"><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">[+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni
(skype)</SPAN></SPAN></SPAN></FONT></DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px; FONT: 12px Helvetica"><BR
style="FONT-SIZE: 12px"></DIV>
<DIV style="MARGIN: 0px"><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">Please, if possible,
don't</SPAN></SPAN></SPAN></FONT><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"> </SPAN></SPAN></SPAN></FONT><FONT
class=Apple-style-span size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">send me MS Word or PowerPoint
attachments</SPAN></SPAN></SPAN></FONT></DIV>
<DIV style="MARGIN: 0px"><FONT class=Apple-style-span size=3><SPAN
class=Apple-style-span style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px">Why? See:</SPAN></SPAN></SPAN></FONT><FONT
class=Apple-style-span size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"><SPAN class=Apple-style-span
style="FONT-SIZE: 12px"> </SPAN></SPAN></SPAN></FONT><A
href="http://www.gnu.org/philosophy/no-word-attachments.html"><FONT
class=Apple-style-span color=#0023e9 size=3><SPAN class=Apple-style-span
style="FONT-SIZE: 12px; COLOR: rgb(0,35,233); khtml-text-decorations-in-effect: underline"><SPAN
class=Apple-style-span
style="FONT-SIZE: 12px; COLOR: rgb(0,35,233); khtml-text-decorations-in-effect: underline"><SPAN
class=Apple-style-span
style="FONT-SIZE: 12px; COLOR: rgb(0,35,233); khtml-text-decorations-in-effect: underline">http://www.gnu.org/philosophy/no-word-attachments.html</SPAN></SPAN></SPAN></FONT></A></DIV>
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