[Wien] Total Energy

[Peter Blaha]

No, the total energy does NOT depend on the reference energy-zero. There 
were some explanations about that on the mailing list.

Chiung-Yuan Lin schrieb:
> Dear all,
>   I  would like to ask a basic question that doesn't seem to have been
> discussed before.
>   In many calculation procedures like mini, optimize, or
> spin-polarized calculation,
> we are comparing the total energy :ENE for different configurations,
> i.e. internal
> structure for mini, lattice constants for optimize, or FM-vs-AFM for
> runsp. To my
> impression, the total energy (and also other energies) is in reference from the
> average coulomb potential in the interstitial region. For surface
> (slab) calculations,
> it makes more sense to me that one should look at the total energy relative to
> the vacuum rather than the interstitial average coulomb. In the UG and among
> many mailing-list discussions, it always states that one should track
> the evaluation
> of the total energy relative to the interstitial average coulomb (the
> :ENE from case.scf) rather than further subtracting from the vacuum
> level.
>   Is there anything wrong in this "popular" statement? Or it's just my
> misunderstanding.
> I hope it can be cleared out here.
> 
> Thanks much,
> Chiung-Yuan
> _______________________________________________
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> Wien at zeus.theochem.tuwien.ac.at
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                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
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Email: blaha at theochem.tuwien.ac.at    WWW: 
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