<div dir="ltr">Hi Dear Expert,<div><br></div><div><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Would someone please suggest me how can I plot temperature dependent phonon dispersion using Quantum Espresso? The paper (10.48550/arXiv.2211.15571) plotted phonon dispersion at different temperatures (Fig 1b) and mentioned that</p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)"><em style="margin:0px;padding:0px;border:0px;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit">"For phonons, we apply a Temperature Dependent Effective Potential method (TDEP) that uses all steps in NVT simulations to construct an effective harmonic force constants (HFCs) that can best describe the potential landscape at certain T. This effective HFCs then intrinsically includes the effect of anharmonic phonon-phonon interactions on the phonon frequency and renormalize the phonon energies. Note that the structure at certain T is the relaxed structure. Fig. 1(b) presents our calculated phonon dispersions at a function of temperature using the effective HFCs."</em></p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">For me the procedures look difficult as I am not familiar with VASP and AIMD. I have gone through the TDEP method (<a href="https://tdep-developers.github.io/tdep/" rel="nofollow noreferrer" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit">https://tdep-developers.github.io/tdep/</a>) where input files preparation depends on VASP.</p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">So, Are there any procedures I can follow to plot the temperature dependent phonon dispersion using Quantum Espresso? I want to share one idea, please suggest me if it looks OK to you.</p><ol style="margin:0px 0px 1.1em 30px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;list-style-position:initial;box-sizing:inherit;color:rgb(12,13,14)"><li style="margin-top:0px;margin-right:0px;margin-left:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit">Run CPMD in QE (NPT ensemble) and get atomic structure at certain Temperature (Temp1)</li><li style="margin-top:0px;margin-right:0px;margin-left:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit">Relax the atoms positions (pw.x, <a href="http://relax.in">relax.in</a>). But the cell structure would not be relaxed as the structure get from CPMD simulation at the Temp1 keep same in all of the consecutive runs.</li><li style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit">Finally, run ph.x,q2r.x and matdyn.x to get the phonon dispersion at the TempT1</li></ol><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">The procedures I described above based on QE, are OK to you?</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Thank you!</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Best</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Md J Hasan</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">PhD Student</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Mechanical Engineering</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">University of Maine</p></div></div>