<div dir="ltr"><div><div><div><div><div><div>Dear Prof Warren,<br><br></div>Yes, QE uses the Allen-Dynes equation to determine the Tc.<br><br></div>I appreciate your additional insight in to the value of lambda.<br><br></div>We're reexamining to ensure that computational errors and noises are ruled out.<br><br></div>Then conclusive inference can be made from the result.<br><br></div>Your response is really appreciated.<br><br></div>Isaiah.<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jul 28, 2017 at 3:18 PM, Warren Pickett <span dir="ltr"><<a href="mailto:wepickett@ucdavis.edu" target="_blank">wepickett@ucdavis.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Isaiah,<br><br></div>I'm not familiar with the workings of QE, but without solution of the full Eliashberg equations it must be using the Allen-Dynes equation (as most do) to obtain Tc. <br><br></div>The basic fact is that with a standard Coulomb repulsion mu-star = 0.10-0.15, with lambda less than 0.3 or so there will be no superconductivity. The A-D equation was not fit to tiny values of Tc and no one should be interested in those results. If non-zero, they will be extremely sensitive to lambda, as you can see. [And you can get nonsensical large values! as you can see]<br></div><br>So just accept that if lambda < 0.3 or so, any results cannot be trusted and its not an interesting el-ph superconductor.<br><br></div>Warren<br></div><div class="gmail_extra"><br clear="all"><div><div class="m_-5473741017543585823gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div><div><br>Warren E. Pickett<br>Distinguished Professor of Physics<br></div><div>Department of Physics<br></div>University of California Davis<br></div>Davis CA 95616, USA<br></div> Cell: 530-220-2138<br></div></div></div></div></div>
<br><div class="gmail_quote"><div><div class="h5">On Fri, Jul 28, 2017 at 12:24 AM, Isaiah Moses <span dir="ltr"><<a href="mailto:imoses87@gmail.com" target="_blank">imoses87@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div dir="ltr"><div><div><div><div><div>Dear everyone,<br><br></div>I did an el-ph calculation of a monoclinic structure and am getting really strange values of Tc . See the result below<br>lambda omega_log T_c<br> 0.00994 112.048 0.10012314E+08 <br> 0.03760 92.373 0.13380511E+10 <br> 0.07564 90.247 0.39802174E+19 <br> 0.09959 89.414 0.19865362E+78 <br> 0.11010 89.463 0.40671597-151 <br> 0.11454 90.329 0.16986711E-65 <br> 0.11678 92.320 0.99512429E-51 <br> 0.11772 94.657 0.29927798E-46 <br> 0.11744 97.141 0.16242032E-47 <br> 0.11619 99.442 0.65514785E-54 <br><br></div>I'm wondering why such values.<br><br></div>Any comment shall be greatly appreciated.<br><br></div>Thanks,<br></div>Isaiah<span class="m_-5473741017543585823HOEnZb"><font color="#888888"><br clear="all"><div><div><div><div><div><div><br>-- <br><div class="m_-5473741017543585823m_3296525048927800365gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div><div>Isaiah Abu Moses<br></div><div>Graduate Student,<br></div>Physics Department,<br></div>University of Ibadan,<br></div>Nigeria<br></div></div></div></div></div></div>
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