Correct total energy value

[IBRAHIM]

Dear All,

With Gaussian smearing, due to the degeneracy of some energy levels (partial occupancies), the total free energy value (F) is some what different from E0 (at 0 sigma).

What is the correct value to be used in that case; total free energy, energy without entropy, or E0 at sigma 0?

I see here wiki/index.php/Fcc_Si, in plotting they use F value; column 1 and 4.
But in case of free atom wiki/index.php/Calculation_of_atoms, in explanation F is not correct.

Also my second question, can we continue with WAVECAR with changing only sigma value?

Many thanks in advance,
Ibrahim

[merzuk.kaltak]

Dear Ibrahim,

If your OUTCAR a line like the following

Code: Select all

energy without entropy =      -21.87505709  energy(sigma->0) =      -21.87293097

-21.8729... eV is the energy you are looking for.

You may read more about SIGMA here,
where it is explained that SIGMA should be as small as possible when having partial occupancies in the system.

[IBRAHIM]

Thank you.