<div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Dear Prof.Blaha and Stefaan, </FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT size=3><FONT face="Times New Roman">Thanks a lot.<SPAN style="mso-spacerun: yes"> </SPAN>Your replies are very helpful.<SPAN style="mso-spacerun: yes"> </SPAN>I applied those in my calculations.<SPAN style="mso-spacerun: yes"> </SPAN>Below this I will give the result, just tell that I am in write track.<SPAN style="mso-spacerun: yes"> </SPAN></FONT></FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT size=3><FONT face="Times New Roman">By Prof.Blaha’s advice, I added few more negative volumes and then I plotted the results, it gave nice parabola and shows that at
-6 only gives the min. energy.<SPAN style="mso-spacerun: yes"> </SPAN></FONT></FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Then I checked the accuracy test to k-point, I repeated the calculation with 1000, 2000 and 3000 for k point.<SPAN style="mso-spacerun: yes"> </SPAN>I <SPAN style="mso-spacerun: yes"> </SPAN>listed result below,</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>k-point<SPAN style="mso-tab-count: 1"> </SPAN><SPAN style="mso-tab-count: 1"> </SPAN>RKM<SPAN style="mso-tab-count: 1"> </SPAN><SPAN style="mso-tab-count: 1"> </SPAN>Enegry<SPAN style="mso-tab-count:
3"> </SPAN>Volume</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><B style="mso-bidi-font-weight: normal"><FONT size=3><FONT face="Times New Roman">1000<SPAN style="mso-tab-count: 2"> </SPAN>6.93<SPAN style="mso-tab-count: 1"> </SPAN><SPAN style="mso-tab-count: 1"> </SPAN>-1707.621751<SPAN style="mso-tab-count: 2"> </SPAN>113.36162<o:p></o:p></FONT></FONT></B></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>2000<SPAN style="mso-tab-count:
2"> </SPAN>6.99<SPAN style="mso-tab-count: 1"> </SPAN><SPAN style="mso-tab-count: 1"> </SPAN>-1707.621552<SPAN style="mso-tab-count: 2"> </SPAN>,,</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>3000<SPAN style="mso-tab-count: 2"> </SPAN>6.61<SPAN style="mso-tab-count: 2"> </SPAN>-1707.621562<SPAN style="mso-tab-count: 2"> </SPAN>,,</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT
face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Therefore, for Ti-bcc system with RMT=2.5, RKMAX=7, <SPAN style="mso-spacerun: yes"> </SPAN>RKM=6.93, <SPAN style="mso-spacerun: yes"> </SPAN>GMAX=12 and k-point =1000 gives the optimized structure with volume V=113.36161 (a = 3.226757A) and <SPAN style="mso-spacerun: yes"> </SPAN>E=-1707.621751Ry.<SPAN style="mso-spacerun: yes"> </SPAN>Is it correct?</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>In the above calculation, I used RMT of Ti is 2.5(default).<SPAN style="mso-spacerun: yes"> </SPAN>From the mailing list (site:
</FONT><A href="http://zeus.theochem.tuwien.ac.at/pipermail/wien/2004-April/002424.html"><FONT face="Times New Roman" color=#800080 size=3>http://zeus.theochem.tuwien.ac.at/pipermail/wien/2004-April/002424.html</FONT></A><FONT face="Times New Roman" size=3>)</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>I changed the RMT of Ti from 2.5 to 2.69 (because nn-distance = 5.39080).</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT size=3><FONT face="Times New Roman">I used remaining parameters as same as the above calculation (RKMAX=7, GMAX=12 and k-point=1000).<SPAN style="mso-spacerun: yes"> </SPAN>Using this data, I am able to run SCF, but not volume optimization with negative volumes because RMT is close to nn-distance (positive volumes give higher energy and it is not possible to get a parabola here).<SPAN style="mso-spacerun: yes"> </SPAN>This calculation is almost look like single point
energy calculation (i.e. it gives the energy of the given structure) and there is not much energy difference from the above calculation.<SPAN style="mso-spacerun: yes"> </SPAN>I listed the result below.<SPAN style="mso-spacerun: yes"> </SPAN></FONT></FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>RMT=2.69, RKMAX=7, RKM=6.89, <SPAN style="mso-spacerun: yes"> </SPAN>GMAX=12 and k-point =1000</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>V=120.59737 (a = 3.294) and E=-1707.621713Ry</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Then how can I do the optimization?</FONT></div>
<div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Thanks in advance.</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>With regards,</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face="Times New Roman" size=3>Santhy Jaiker</FONT></div> <div class=MsoNormal style="MARGIN: 0in 0in 0pt"><o:p><FONT face="Times New Roman" size=3> </FONT></o:p></div><BR><BR><B><I>Peter Blaha <pblaha@theochem.tuwien.ac.at></I></B> wrote: <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Hi,<BR><BR>I hope it is clear that you CANNOT use min_lapw for your bcc Ti example.<BR><BR>With respect to the
volume optimization, I don't see anything bad.<BR><BR>Specifying RKMAX does not fix RKMAX to this value, it just guarantees <BR>that it does not get bigger than what you specified, but when changing <BR>the lattice parameter, it is natural that RKMAX changes.<BR><BR>You shoulds add a few more negative volumes (-9 -12 maybe -15) and then <BR>plot the results because it seems the minimum is near -6. When you get a <BR>nice parabola it seems ok, if not it may happen because of too low RKMAX <BR>(gotro 7.5, 8, up to 9) or to few k-points (100 is very little).<BR><BR>> I am a new user of wien2k. I had gone through the FAQ and L.D. Marks <BR>> notes for optimization. I started with small system like Ti-BCC. <BR>> Before going to mini_lapw, I tried the accuracy test as same as given <BR>> in the site http://www.wien2k.at/events/ws2006/Exercises.pdf.<BR>> <BR>> I gave lattice parameter= 3.294A°, RMT=2.5(default), RKMAX=7(default), <BR>> k-point=1000 and
Gmax=12(default) for Ti-BCC system. I tried the same <BR>> step in the above site,<BR>> STEP 1: run x optimize and generate 5 structures (-6, -3, 0, 3, 6 % <BR>> volume change)<BR>> STEP2: edit “optimize.job”.<BR>> STEP3: run optimize.job and plot the results. <BR>> I got<BR>> SCF File RKM Energy<BR>> Vol -6.0.scf *6.93 -1707.621717*<BR>> Vol -3.0.scf 6.85 -1707.621662<BR>> Vol 0.0.scf 6.79 -1707.621239<BR>> Vol 3.0.scf 6.72 -1707.619926<BR>> Vol 6.0.scf 6.65 -1707.618133<BR>> <BR>> Energy is high when RKM is 6.93. Since I changed RKMAX=6.93 in Ti.in1 <BR>> file and I didn’t change any other parameter. I repeated those 3 steps. <BR>> I got<BR>> <BR>> SCF File RKM Energy<BR>> Vol -6.0.scf *6.93 -1707.620994*<BR>> Vol -3.0.scf 6.85 -1707.620941<BR>> Vol 0.0.scf 6.79 -1707.620476<BR>> Vol 3.0.scf 6.72 -1707.619422<BR>> Vol 6.0.scf 6.65 -1707.617423<BR>> <BR>> Here I observed that even though same RKMAX
(=6.93) gives different <BR>> energy. And I couldn’t keep RKMAX as constant. Since, during SCF <BR>> calculation it changes.<BR>> <BR>> Sorry I took more of your time. I have some experience to handle CASTEP <BR>> (in windows mode). But I couldn't correlate things in WIEN2k. <BR>> <BR>> It will be really helpful, if you tell, how to do the accuracy test for <BR>> RKMAX.<BR>> <BR>> Thanks in advance.<BR>> <BR>> Santhy Jaiker<BR>> <BR>> <BR>> ------------------------------------------------------------------------<BR>> Here’s a new way to find what you're looking for - Yahoo! Answers <BR>> <HTTP: in.answers.yahoo.com *http: yanswers in mail us.rd.yahoo.com /><BR>> <BR>> <BR>> ------------------------------------------------------------------------<BR>> <BR>> _______________________________________________<BR>> Wien mailing list<BR>> Wien@zeus.theochem.tuwien.ac.at<BR>>
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<BR>_______________________________________________<BR>Wien mailing list<BR>Wien@zeus.theochem.tuwien.ac.at<BR>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<BR></BLOCKQUOTE><BR><BR><BR>with love,<br> K. Santhy<br> <br style="color: rgb(191, 95, 0);"><span style="color: rgb(185, 185, 185);"> **********************************************</span><br style="color: rgb(185, 185, 185);"><span style="color: rgb(185, 185, 185);"> A truly happy person is one</span><br style="color: rgb(185, 185, 185);"><span style="color: rgb(185, 185, 185);"> who can enjoy the scenery on a detour</span><br style="color: rgb(185, 185, 185);"><span style="color: rgb(185, 185, 185);"> **********************************************</span><br><p> Send free SMS to your Friends on Mobile from your Yahoo! Messenger. Download Now! http://messenger.yahoo.com/download.php