<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Hello dear users and developers of QE,</div><div class=""><br class=""></div><div class="">I am trying to calculate phonons using very good structure (tightly optimized, matching the experimental one, etc), but whatever I do the result is:</div><div class=""><span style="color: rgb(53, 249, 53); font-family: Menlo; font-size: 16px; background-color: rgba(0, 0, 0, 0.772549);" class=""><br class=""></span></div><div class=""><span style="color: rgb(53, 249, 53); font-family: Menlo; font-size: 16px; background-color: rgba(0, 0, 0, 0.772549);" class=""> </span><span style="color: rgb(53, 249, 53); font-family: Menlo; font-size: 16px; background-color: rgba(0, 0, 0, 0.772549);" class="">%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</span></div><div style="margin: 0px; font-size: 16px; line-height: normal; font-family: Menlo; color: rgb(53, 249, 53); background-color: rgba(0, 0, 0, 0.772549);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> Error in routine cdiaghg (448):</span></div><div style="margin: 0px; font-size: 16px; line-height: normal; font-family: Menlo; color: rgb(53, 249, 53); background-color: rgba(0, 0, 0, 0.772549);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> S matrix not positive definite</span></div><div class=""><span style="color: rgb(53, 249, 53); font-family: Menlo; font-size: 16px; background-color: rgba(0, 0, 0, 0.772549);" class=""> </span><span style="color: rgb(53, 249, 53); font-family: Menlo; font-size: 16px; background-color: rgba(0, 0, 0, 0.772549);" class="">%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</span></div><div class=""><br class=""></div><div class="">I varied:</div><div class="">- number of processors (with too large # of processors similar issues are reported)</div><div class="">- ecutrho increasing it up to ecutwfc*15</div><div class="">- different smearings schemes (the system is a narrow band gap semiconductor)</div><div class="">- different diagonalization procedures (from my personal experience: david fail sometimes where cg saves the day)</div><div class="">- used nosym=.true.</div><div class=""><br class=""></div><div class="">I would highly appreciate any thoughts on the nature of this mistake happening in the very beginning of phonon calculation.</div><div class=""><br class=""></div><br class=""><div class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Best,<br class="">Alex.<br class="">___<br class="">Aleksandra Oranskaia (M.Sc.)<br class="">ChemS PhD student, KAUST<br class="">Phone: +966 50 1335254<br class=""><br class=""><br class=""></div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class=""></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline">
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