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<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">It is with great trepidation that I post these kinds of questions on PWforum. I always fear being scolded by</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Paolo and/or Axel for not looking at</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> past</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">for</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">a postings</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> or</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> within the</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> intricacies of</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">the code.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> (No, I missed seeing</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">that covered in the posting of</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">28</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">June</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> 1914</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">…</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">I was otherwise engaged).</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">To be serious, my present posting is</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> motivated by the late May discussions on</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">Phonon DOS in noncubic materials</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">I have started some e-p</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> ph.x calculations on</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">several</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">interesting</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> transition metal oxides</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">using</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> SCF eigenstates computed with LDA+U</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> implemented, of cubic and/or tetragonal rocksalt symmetry. The</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">end story intention is to calculate the Eliashberg lambda. Why would one ever want to do this? Think superconductivity.</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Issues:</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">1) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"> I assume ph.x can handle spin polarized</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">states</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, because that</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s the basis of</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Example02 and it seems to work OK.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> </SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">2) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"> It</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">(ph.x)</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">also</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">seems to work</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">with</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">la2</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">F and lda_plus_u set .true.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, that is, it generates gammas and lambdas</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> without barfing</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, for cubic and tetragonal AFII</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">primitive cells. So far, so good.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">3) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Question</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">…</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">why is it necessary to do two scf runs a la Example07, one to set a DOS flag for separate use later</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, and another to set the k-point grid for a</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">subsequent</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> el-ph run</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> with ph.x? I know there might some resource issues for</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">serious</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> calculations, but for Example07, one scf with</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">la2F</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">on</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> and an MP grid of order 12,</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">seems to</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> work just fine.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> At least for a</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">non-serious</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> calculation.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">4) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Next we bring C(q) from the output of ph.x to</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">real space</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> with q2r.x.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">5) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Now it gets dicey.</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> The following I haven</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">t tried yet.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">6) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">The matdyn.x calculation to compute the frequency dependent component of the Eliashberg</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">kernel</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> uses a</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">real space</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> sampling grid</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">…</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">in the case of Example07 of size 19. How is this grid determined? It looks to me like it</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s spanni</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">ng some high symmetry directions</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">within</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"> the Al unit cell</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">. Is there an algorithm to calculate such for general symmetry other than Al</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> (or fcc)</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> (e.g., an analog to MP</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> sampling</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, or FS</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> BZ</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> sampli</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">ng</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">), or is such just a user-selected symmeterized</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">wet finger in the wind?</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">7) </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">Lastly, here</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s where I really get confused and appreciate Dr. Prasad</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s posting. Which</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">dos</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> calculation is being referred to</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">…</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">the scf run with la2F set true, or</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">a restriction on the input to the</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">final</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> matdyn.x run with dos set tru</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">e?</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">What</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">needed is a user</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s manual for matdyn (sorry, Paolo), or, better yet, three or</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">four more examples like 07 on non-cubic but otherwise s</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">imple symmetries</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">and simple basis orbital</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> sets</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">with more than one atom per unit cell</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">…</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">like MgB2!</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">Ciao, -Paul</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><B><I></I></B></SPAN><SPAN LANG="en-us"><B><I></I></B></SPAN><SPAN LANG="en-us"><B><I></I></B></SPAN><B><I><SPAN LANG="en-us"></SPAN></I></B></P>
<P DIR=LTR><SPAN LANG="en-us"><B><I></I></B></SPAN><SPAN LANG="en-us"><B><I></I></B></SPAN><SPAN LANG="en-us"><B><I></I></B></SPAN><B><I><SPAN LANG="en-us"><FONT SIZE=4 FACE="Comic Sans MS">Paul M. Grant, PhD</FONT></SPAN></I></B><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><B><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Principal, W2AGZ Technologies</FONT></SPAN></B><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><B><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Visiting Scholar, Applied Physics, Stanford University</FONT></SPAN></B><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><B><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">EPRI Science Fellow (Retired)</FONT></SPAN></B><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><B><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">IBM Research Staff Member Emeritus</FONT></SPAN></B><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><A HREF="mailto:w2agz@pacbell.net"><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B></B></SPAN><B><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">w2agz@pacbell.net</FONT></SPAN></B><SPAN LANG="en-us"></SPAN></A><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
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