<div dir="ltr">I'm not aware of the system under study, but if it is a new material, then one should calculate phonons to check the stability.<div><br></div><div>If the system is already synthesized and you are studying the effect of doping/adsorption, then binding/formation/cohesive/adsorption energy(ies) is(are) enough.</div><div><br></div><div>Also, keep in mind that the value (-/+) depends on the order of the equation. </div><div><br></div><div>Regards</div><div>Saif</div><div>Dept. Physics, UFJF, Brazil </div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 14, 2017 at 8:26 AM, Rajesh <span dir="ltr"><<a href="mailto:creativeidleminds@gmail.com" target="_blank">creativeidleminds@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear Saif Ullah,<div>The negative value of binding energy is not enough to predict stability? Why do we need phonon calculations for that?</div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 14, 2017 at 2:37 PM, Saif Ullah <span dir="ltr"><<a href="mailto:kiterunner7@gmail.com" target="_blank">kiterunner7@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto">Dear,<div dir="auto"><br><div dir="auto">Ebin = Etot - ENi - EBi - 3EO</div><div dir="auto"><br></div><div dir="auto">Or depends on how you write.</div><div dir="auto"><br></div><div dir="auto">For stability, you need to calculate phonons.</div><div dir="auto"><br></div><div dir="auto">Regards</div><div dir="auto">Saif</div><div dir="auto">Dept. Physics, UFJF, Brazil</div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 14 Nov 2017 6:51 am, "Sudha Priyanka" <<a href="mailto:sudhapriyanga24@gmail.com" target="_blank">sudhapriyanga24@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">


        
        
        
        


<h1 class="m_-5234193498506494036m_-9013512421085142211m_-434948305713938781gmail-western">Can anyone suggest how to calculate binding 
energy of my crystal NaBiO₃by using Quantum Espresso?</h1>
<p style="margin-bottom:0cm">I have successfully completed the SCF
of NaBiO₃ using GGA-PBE. I have checked the SCF file and
found the energy value : -333.03842 Ry/unit cell.</p>
<p style="margin-bottom:0cm">I have performed total energy
calculation of isolated atoms Na, Bi and O and found energy value as
-192.232097 Ry, -141.20403847 Ry, -126.84166 Ry respectively.</p>
<p style="margin-bottom:0cm">Now, please guide me how to calculate
the binding energy of NaBiO₃.</p>
<p style="margin-bottom:0cm">Also I would like to know what should
be the binding energy value for a crystal to be stable? It should be positive or negative value?<br></p>
<p style="margin-bottom:0cm">Please suggests formula to calculate
binding energy for this perovskite and suggest me some link or any
related papers.</p>
<p style="margin-bottom:0cm">Your help will be appreciated</p><p style="margin-bottom:0cm">Thanks in advance</p><p style="margin-bottom:0cm">Sudha Priyanka<br></p>
<p style="margin-bottom:0cm"><br>

</p>

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