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<p style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);"><br>
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<span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);">Thank you so much for
your generous offer to share the. I would love to take a look at it.</span></p>
<p style="text-align: left; margin: 1.25em 0px; border-width: 0px; border-style: solid; border-color: rgb(217, 217, 227); background-color: rgb(255, 255, 255);" class="elementToProof">
<span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);">Could you please send
me the spreadsheet ? It would be a great help for my current project.</span></p>
<p style="text-align: left; margin: 1.25em 0px; border-width: 0px; border-style: solid; border-color: rgb(217, 217, 227); background-color: rgb(255, 255, 255);">
<span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);">Best,</span></p>
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<span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);">Elham Rezaee<br>
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<span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0);"> </span><span style="letter-spacing: normal; font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif; font-size: 10pt; font-weight: 400; color: rgb(0, 0, 0);">PhD
student at UNB/Canada</span></p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Marcelo Falcão de Oliveira via users <users@lists.quantum-espresso.org><br>
<b>Sent:</b> Wednesday, November 22, 2023 2:43 PM<br>
<b>To:</b> Mpayami <mpayami@aeoi.org.ir>; Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org><br>
<b>Subject:</b> Re: [QE-users] Guidance Required for Stiffness Matrix Calculation from Stress and Strain Data</font>
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<span>❗</span><span style="color:#ffffff; font-weight:bold">External message:</span> Use caution.</div>
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<div dir="ltr">Dear Rezaee,
<div><br>
</div>
<div> If it helps I have an excel spreadsheet that automatically calculates the elastic constants for you. You just copy and paste data from QE to the spreadsheet and vice versa. It automatically calculates 6 possible distortions for your unit cell, thus you
run the QE calculations and paste back the stress matrices, thus you'll have all elastic constants. It also checks the stiffness matrix for elastic stability (eigenvalues) as well as calculates averages of Voigt, Reuss and Voigt-Reuss-Hill. The references
used for all that are also cited in the spreadsheet. Just let me know. </div>
<div><br>
</div>
<div>Regards, </div>
</div>
<br>
<div class="x_gmail_quote">
<div dir="ltr" class="x_gmail_attr">Em qua., 22 de nov. de 2023 às 14:46, Mpayami via users <<a href="mailto:users@lists.quantum-espresso.org">users@lists.quantum-espresso.org</a>> escreveu:<br>
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<blockquote class="x_gmail_quote" style="margin:0px 0px 0px 0.8ex; border-left:1px solid rgb(204,204,204); padding-left:1ex">
<div dir="auto" style="font-size:13px">
<div>Dear Elham,</div>
<div><br>
</div>
<div>Hi.</div>
<div>Once I was interested to do such direct calculations, I followed the method outlined in the following link:</div>
<div><br>
</div>
<div><a href="https://docs.materialsproject.org/methodology/materials-methodology/elasticity" target="_blank">https://docs.materialsproject.org/methodology/materials-methodology/elasticity</a></div>
<div><br>
</div>
<div>as well as the notes provided by Prof. Andrea Dal Corso in the DOC folder of Thermo_pw.</div>
<div><br>
</div>
<div>Secondly, as Prof. Nicola Marzari suggested in reply to your post, please mention your affiliation in your posts.</div>
<div><br>
</div>
<div>Hope that helps.</div>
<div><br>
</div>
<div>Besr regards, <br>
</div>
<div>
<div>Mahmoud Payami</div>
<div><br>
</div>
<div>NSTRI, AEOI</div>
<div>Tehran, Iran</div>
<div>Email: <a href="mailto:mpayami@aeoi.org.ir" target="_blank">mpayami@aeoi.org.ir</a></div>
<div>Phone: +98(0)2182066504</div>
<div>------------------------------------</div>
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----- Original Message -----</div>
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From: Elham Rezaee (<a href="mailto:elham.rezaee@unb.ca" target="_blank" style="font-family:Helvetica,sans-serif; font-size:12px; font-weight:300; line-height:150%; color:rgb(0,136,204); text-decoration:none">elham.rezaee@unb.ca</a>)<br>
Date: 01/09/1402 15:54<br>
To: <a href="mailto:users@lists.quantum-espresso.org" target="_blank" style="font-family:Helvetica,sans-serif; font-size:12px; font-weight:300; line-height:150%; color:rgb(0,136,204); text-decoration:none">
users@lists.quantum-espresso.org</a><br>
Subject: <span style="font-family:Helvetica,sans-serif; font-size:12px; line-height:150%; color:rgb(51,51,51); text-decoration:none; font-weight:bold">
[QE-users] Guidance Required for Stiffness Matrix Calculation from Stress and Strain Data</span></div>
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<div>
<p class="x_MsoNormal">Hi Team,</p>
<p class="x_MsoNormal">I am reaching out for some clarification on the procedure for calculating the stiffness matrix. I understand that it involves applying various strains to our crystalline structure and then measuring the corresponding stress matrices,
but I am unsure about the details of this process.</p>
<p class="x_MsoNormal">My plan is to apply strains in the range of -1% to +1%. The approach, as I understand it, is to begin by adjusting the 'a' parameter in the x-direction by +1%, and then proceed to modify the other cell parameters such as 'ay', and so
on. However, I am unclear about how to systematically organize the relationship between each applied strain and the resulting 3x3 stress tensor. This organization is crucial for the accurate assembly of the stiffness matrix.</p>
<p class="x_MsoNormal">Additionally, the sequence in which the cell parameters should be deformed is a point of uncertainty for me. A clear and systematic approach is necessary to ensure the correct construction of the stiffness matrix, which is essential for
calculating the elastic properties of our material.</p>
<p class="x_MsoNormal">I aim to perform these calculations independently to acquire the stiffness matrix, like those found in the Material Project database, to further evaluate the material's elastic properties.</p>
<p class="x_MsoNormal">Could you please provide guidance or point me to resources that could help clarify how to properly organize the strain and stress matrices and determine the sequence of cell parameter deformations?</p>
<p class="x_MsoNormal">Thanks,<br>
Elham</p>
</div>
<hr>
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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>
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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">
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<div dir="ltr"><span style="font-size:12.8px">Marcelo Falcão de Oliveira</span><br style="font-size:12.8px">
<span style="font-size:12.8px">Professor Associado</span><br style="font-size:12.8px">
<span style="font-size:12.8px">Departamento de Engenharia de Materiais</span><br style="font-size:12.8px">
<span style="font-size:12.8px">EESC - USP</span><br style="font-size:12.8px">
<div dir="ltr" style="font-size:12.8px">Av. João Dagnone, 1100, Jd. Sta Angelina</div>
<div dir="ltr" style="font-size:12.8px">CEP: 13563-120, São Carlos - SP - Brasil</div>
<span style="font-size:12.8px">e-mail: </span><a href="mailto:marcelo.falcao@usp.br" target="_blank" style="font-size:12.8px">marcelo.falcao@usp.br</a><br style="font-size:12.8px">
<span style="font-size:12.8px">Fone: (16) 3373-9583</span><br style="font-size:12.8px">
<span style="font-size:12.8px">Fax: (16) 3373-9590</span><br style="font-size:12.8px">
<span style="font-size:12.8px">Agenda: </span><a href="http://www.google.com/calendar/embed?src=marcelo.falcao%40usp.br&ctz=America/Sao_Paulo&mode=week" target="_blank" style="font-size:12.8px">http://www.google.com/calendar/embed?src=marcelo.falcao%40usp.br&ctz=America/Sao_Paulo&mode=week</a><br>
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