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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Way back in the summer of 2008, I posted several threads regarding the possibility of eventually incorporating into QE a tool to compute the electron-phonon interaction in Mott-Hubbard systems (especially doped) following an appropriate LDA+U scf computation. Yet I see such a tool still remains unavailable up to the present QE-5.1.2 release. At the time (2008), I had a very pleasant e-mail exchange with the late Eyvaz Isaev. I regret not having the opportunity to meet him in person before his passing, a great loss to our community. Eyvaz agreed such a tool would indeed be useful, but, at the time, there was a need for more urgent fixes to the el-ph package. I was also supported in my request by several others in the QE community, for example, Matteo Cocionni, Nicola Marzari and Alex Kohlmeyer. I do recall a posting from Andrea Floris at physic.fu-berlin.de that an implementation would soon be available, and I even offered to be a beta-tester. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I do not believe a DFT-implemented phonon-spinon coupling tool is available on any of the other usual well-known production packages (at least those of which I am familiar), such as VASP, WIEN2k, Abinit, CASTEP, nor within response function packages like YAMBO, Gitorius, Octopus…again those I’m familiar with. Should I be presently “ignorant” of other packages that may contain this feature, please point me appropriately.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Why would availability of such a tool be a critical contribution to condensed matter physics?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I maintain the great remaining mystery held over from 20<sup>th</sup> century CMP is the pairing mechanism of high temperature superconductivity in doped Mott-Hubbard insulators (for background, please read my 2011 editorial in Nature, “The Great Quantum Conundrum,” (<a href="http://w2agz.com/Publications/Opinion%20&%20Commentary/W2AGZ/Nature/%282011%29%20The%20great%20quantum%20conundrum,%20Nature%20476,%2037.pdf)">http://w2agz.com/Publications/Opinion%20&%20Commentary/W2AGZ/Nature/%282011%29%20The%20great%20quantum%20conundrum,%20Nature%20476,%2037.pdf)</a>).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Wouldn’t it be exciting if the QE community could aid in the solution of this “Conundrum?”<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Regards, -Paul<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b><i><span style='font-size:13.5pt;font-family:"Comic Sans MS";color:#1F497D'>Paul Michael Grant, PhD<o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-family:"Comic Sans MS";color:#1F497D'>Physicist and Science Writer<o:p></o:p></span></i></b></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Senior Life Fellow, American Physical Society<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Fellow, Institute of Physics, United Kingdom<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>APS Distinguished Lecturer on Applications of Physics (2014-15) <o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Staff Associate, Jet Propulsion Laboratory, NASA (2011-15)</span></b><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Visiting Scholar, Applied Physics, Stanford (2005-2008)</span></b><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>EPRI Science Fellow (Retired)</span></b><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>IBM Research Staff Member/Manager Emeritus</span></b><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Principal, W2AGZ Technologies<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'><a href="mailto:w2agz@w2agz.com"><span style='color:black'>w2agz@w2agz.com</span></a></span></b><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'><a href="http://www.w2agz.com/"><b><span style='color:black'>http://www.w2agz.com</span></b></a></span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>