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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>To the Forum, I&#8217;m sure my inquiry will wind up on the doorstep of Eyvaz, so I&#8217;ll address this directly to him shortly.<o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal>But firstly, let me echo Stephano&#8217;s New Year&#8217;s Greeting...it could not have been put more eloquently...unless it had been in Italian!&nbsp; In fact, I think we can all celebrate again in another two weeks on the occassion of the &#8220;old Russian New Year&#8217;s.&#8221; <o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal>I, too, am a fan of Jean Piaget, and one my favorite quotes (in English) is, &#8220;Scientific knowledge is in perpetual evolution; it finds itself changed from one day to the next.&#8221;&nbsp; The Democritos movement is at the forefront of such evolution worldwide, and, in fact, imho, thus deserves the Peace Prize much more than the recipient two years ago.<o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal>OK...to business.&nbsp; Eyvaz, <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Thanks very much for creating PlotPhon.&nbsp; It&#8217;s a great contribution to the &#8220;QE toolbox.&#8221;<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Could you supply us the input files for pw.x and ph.x that created the output for q2r.x to process into the *.fc files for the &#8220;three examples?&#8221;<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>3)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>In particular, and especially, for AL_FCC and Al444.fc.&nbsp; I typically use the Al parameters of Example 07 and the *.fc files don&#8217;t match, even when I use your value of the lattice constant.&nbsp; (Ex07 uses a lattice constant of 7.50 au, and PlotPhon uses 7.653 (??), while I usually use 4.050 (Ang))<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>4)<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Now for a question likely very naive...<o:p></o:p></p><p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>a.<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Al444.fc contains something like 584 permutations on &#8220;interatomic force constants,&#8221; indexed according the 4x4x4 MP input.&nbsp; It seems to me that there are (perhaps) two different nearest-neighbor Al-Al distances in the fcc unit cell, so...<o:p></o:p></p><p class=MsoListParagraph style='margin-left:1.0in;text-indent:-.25in;mso-list:l0 level2 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>b.<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Is there a simple way to relate the *.fc output into pairwise &#8220;interatomic force constants?&#8221;<o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal>OK...Otro vez, Feliz Anyo Nuevo a los Todos y mucho mas in el Futuro.<o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo4'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Paul Grant<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo4'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]>Senior Life Fellow, American Physical Society<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo4'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]><a href="mailto:w2agz@w2agz.com">w2agz@w2agz.com</a><o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo4'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><![endif]><a href="http://www.w2agz.com">www.w2agz.com</a><o:p></o:p></p><p class=MsoListParagraph><o:p>&nbsp;</o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p></div></body></html>