<div dir="ltr"><div><div><div><div><div><div><div><div><br clear="all"></div>Respected Experts,<br><br></div> In the article PRB 71, 205214 (2005) authored by Nicolas Mounet and Nicola Marzari, in equation 7, it is mentioned that, <br><br></div>Helmholtz free energy F(a, T)=E(a) + Fvib(T)<br><br></div>where, 'a' is geometrical degrees of freedom, 'T' is temperature, 'Fvib' is vibrational free energy, and 'E(a)' is the ground state energy or energy of static lattice as a function of cell parameters. <br><br></div>Can you please guide me how to calculate E(a)? Is there an example of it in qe-6.2-examples?<br><br></div><div>Also I take this opportunity to thank Dr. Lorenzo Paulatto who guided me to the appropriate examples in qe-6.2-examples to calculate the Fvib.<br></div><div><br></div>Thanking you,<br></div>Yours sincerely,<br></div>Krishnendu<br><div><div><div><div><div><div><div><div><div><div><br>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div>Dr. Krishnendu Mukherjee,</div></div><div><br></div><div>Principal Scientist,</div><div>CSIR-NML,</div><div>Jamshedpur.</div></div></div></div></div></div></div></div></div>
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