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Dear Yipeng,<br>
<br>
My guess: Maybe this is due to the fact that a tetrahedron is a 3D object which cannot be properly created by points in a 2D plane...<br>
<br>
Kind regards<br>
<br>
Thomas Brumme<br>
<br>
TU Dresden, Germany
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>Von:</b> users <users-bounces@lists.quantum-espresso.org> im Auftrag von 526587466 <526587466@qq.com><br>
<b>Gesendet:</b> Sonntag, 13. Juni 2021 11:14:19<br>
<b>An:</b> QEforum<br>
<b>Betreff:</b> [QE-users] phonon of 2D materials by tetrahedra_opt method</font>
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Dear All,</div>
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<div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">
When doing a test of graphene by the tetrahedra_opt method, I fount it prints the complete negative frequencies if using the nq (6x6x1), while right for nq (6x6x2) but cost more times. </div>
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So, what's wrong? How to calculate the phonon of 2D materials by tetrahedra_opt method. Should the number of nq3 be larger than 1 for the tetrahedra_opt method? </div>
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Thanks.</div>
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Best regards,</div>
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Yipeng</div>
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<div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">
Henan Normal University, Xinxiang China</div>
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