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.
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. Also, keep in mind that the value (-/+) depends on the order of the equation. Regards Saif Dept. Physics, UFJF, Brazil On Tue, Nov 14, 2017 at 8:26 AM, Rajesh <[email protected]> wrote: > Dear Saif Ullah, > The negative value of binding energy is not enough to predict stability? > Why do we need phonon calculations for that? > > On Tue, Nov 14, 2017 at 2:37 PM, Saif Ullah <[email protected]> wrote: > >> Dear, >> >> Ebin = Etot - ENi - EBi - 3EO >> >> Or depends on how you write. >> >> For stability, you need to calculate phonons. >> >> Regards >> Saif >> Dept. Physics, UFJF, Brazil >> >> On 14 Nov 2017 6:51 am, "Sudha Priyanka" <[email protected]> >> wrote: >> >>> Can anyone suggest how to calculate binding energy of my crystal NaBiO3 by >>> using Quantum Espresso? >>> >>> 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. >>> >>> 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. >>> >>> Now, please guide me how to calculate the binding energy of NaBiO3. >>> >>> 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? >>> >>> Please suggests formula to calculate binding energy for this perovskite >>> and suggest me some link or any related papers. >>> >>> Your help will be appreciated >>> >>> Thanks in advance >>> >>> Sudha Priyanka >>> >>> >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> [email protected] >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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