<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">You must preserve the proportion --and, if the displacements are complex, the phase differences- among the mode components. </span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;"><br>
</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
Your procedure doesn't do that unless you write the displaced geometry in fractional coordinates and your system is orthorhombic. </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
It's much simpler to use alat coordinates so that you can add the scaled displacement as it is. </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
Pietro </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">
</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>Da:</b> users <users-bounces@lists.quantum-espresso.org> per conto di Piotr Szkudlarek <p.szkudlarek@cent.uw.edu.pl><br>
<b>Inviato:</b> mercoledì 25 gennaio 2023 14:54<br>
<b>A:</b> Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org><br>
<b>Oggetto:</b> Re: [QE-users] R: R: Reading displacements from the matdyn.modes file</font>
<div> </div>
</div>
<div>
<div dir="ltr">Dear Pietro,
<div>to create the displaced geometries, I added the 1st, 3rd and 5th number in the matrix divided by x, y and z cell sizes and then multiplied by an arbitral scaling factor (in my case - 0.1)). Is that a proper way to create the displaced geometry?</div>
<div>Yours sincerely.,</div>
<div>Piotr Szkudlarek</div>
</div>
<br>
<div class="x_gmail_quote">
<div dir="ltr" class="x_gmail_attr">śr., 25 sty 2023 o 14:48 Pietro Davide Delugas <<a href="mailto:pdelugas@sissa.it">pdelugas@sissa.it</a>> napisał(a):<br>
</div>
<blockquote class="x_gmail_quote" style="margin:0px 0px 0px 0.8ex; border-left:1px solid rgb(204,204,204); padding-left:1ex">
<div class="x_msg-3743501196263887508">
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
Dear Piotr </div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
It is just a normalized 3Xnat vector --normalized such that the sum of the squared moduli of all displacements yields one. They give you the relative amplitudes and phases of the atomic displacements in that mode. The net amplitude would depend on the energy
stored in that mode and its reduced mass. </div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
Hope it helps </div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
Pietro</div>
<div id="x_m_-3743501196263887508appendonsend"></div>
<hr style="display:inline-block; width:98%">
<div id="x_m_-3743501196263887508divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Da:</b> users <<a href="mailto:users-bounces@lists.quantum-espresso.org" target="_blank">users-bounces@lists.quantum-espresso.org</a>>
per conto di Piotr Szkudlarek <<a href="mailto:p.szkudlarek@cent.uw.edu.pl" target="_blank">p.szkudlarek@cent.uw.edu.pl</a>><br>
<b>Inviato:</b> mercoledì 25 gennaio 2023 13:22<br>
<b>A:</b> Quantum ESPRESSO users Forum <<a href="mailto:users@lists.quantum-espresso.org" target="_blank">users@lists.quantum-espresso.org</a>><br>
<b>Oggetto:</b> Re: [QE-users] R: Reading displacements from the matdyn.modes file</font>
<div> </div>
</div>
<div>
<div dir="ltr">Dear Pietro,
<div>Thank you very much for your answer. I have another question: are those numbers in Angstrom or what units?</div>
<div>Regards,</div>
<div>Piotr Szkudlarek</div>
<div><br>
</div>
</div>
<br>
<div>
<div dir="ltr">pon., 23 sty 2023 o 11:28 Pietro Davide Delugas <<a href="mailto:pdelugas@sissa.it" target="_blank">pdelugas@sissa.it</a>> napisał(a):<br>
</div>
<blockquote style="margin:0px 0px 0px 0.8ex; border-left:1px solid rgb(204,204,204); padding-left:1ex">
<div>
<div dir="ltr">
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">Hello Piotr </span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">The displacements' components are complex numbers; thus, six floats. </span></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0); background-color:rgb(255,255,255)">
Pietro </div>
<div id="x_m_-3743501196263887508x_m_-2487008218803277488appendonsend"></div>
<hr style="display:inline-block; width:98%">
<div id="x_m_-3743501196263887508x_m_-2487008218803277488divRplyFwdMsg" dir="ltr">
<font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Da:</b> users <<a href="mailto:users-bounces@lists.quantum-espresso.org" target="_blank">users-bounces@lists.quantum-espresso.org</a>> per conto di Piotr Szkudlarek <<a href="mailto:p.szkudlarek@cent.uw.edu.pl" target="_blank">p.szkudlarek@cent.uw.edu.pl</a>><br>
<b>Inviato:</b> lunedì 23 gennaio 2023 10:55<br>
<b>A:</b> Quantum ESPRESSO users Forum <<a href="mailto:users@lists.quantum-espresso.org" target="_blank">users@lists.quantum-espresso.org</a>><br>
<b>Oggetto:</b> [QE-users] Reading displacements from the matdyn.modes file</font>
<div> </div>
</div>
<div>
<div dir="ltr">Dear QE community,
<div>I would like to ask what is the meaning of 6 floats in matdyn.modes file. I can imagine that 3 of them show the coordinates of the displacements, but what are the other three? Also, which of them are the ones telling about the coordinates of the displacement?</div>
<div>Best,</div>
<div>Piotr Szkudlarek,</div>
<div>University of Warsaw</div>
</div>
</div>
</div>
_______________________________________________<br>
The Quantum ESPRESSO community stands by the Ukrainian<br>
people and expresses its concerns about the devastating<br>
effects that the Russian military offensive has on their<br>
country and on the free and peaceful scientific, cultural,<br>
and economic cooperation amongst peoples<br>
_______________________________________________<br>
Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu" rel="noreferrer" target="_blank">www.max-centre.eu</a>)<br>
users mailing list <a href="mailto:users@lists.quantum-espresso.org" target="_blank">
users@lists.quantum-espresso.org</a><br>
<a href="https://lists.quantum-espresso.org/mailman/listinfo/users" rel="noreferrer" target="_blank">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div>
</blockquote>
</div>
</div>
</div>
_______________________________________________<br>
The Quantum ESPRESSO community stands by the Ukrainian<br>
people and expresses its concerns about the devastating<br>
effects that the Russian military offensive has on their<br>
country and on the free and peaceful scientific, cultural,<br>
and economic cooperation amongst peoples<br>
_______________________________________________<br>
Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu" rel="noreferrer" target="_blank">www.max-centre.eu</a>)<br>
users mailing list <a href="mailto:users@lists.quantum-espresso.org" target="_blank">
users@lists.quantum-espresso.org</a><br>
<a href="https://lists.quantum-espresso.org/mailman/listinfo/users" rel="noreferrer" target="_blank">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div>
</blockquote>
</div>
</div>
</body>
</html>