[WIEN]Why Fermi Energy is positive

[Jiang Jun]

Anyway thank you very much for your soon reply!

Yeah.You are quite right,Energies of free electrons are always positive.
But,E(tot)=E(kinetic)+E(potential)

Here,E(Kinetic)>0.
Then if E(Potential)<0, Maybe E(tot) be <0.

In fact,I Do NOT suspect that there were something wrong with WIEN2K that 
leads to the Fermi-Energy be positive and What I wonder and much more care 
is: Where is the ZERO point of Potential in the Crystial-Calculation and What 
is its Physical means?

I believe just for the choice of the point of reference-potentical,part of 
the EIGENVALUES become positive.Maybe this is a elementary question in LAPW.

Best wishes!
                                               Sincerely Jun
> Energies of free electrons are always positive as the kinetic energy 1/2 m 
v^2 cannot be negytive (if neglecting inelastic approximations).
> 

----
    Welcome to Rarelab in PKU (http://hpsv.pku.edu.cn)
    Welcome to Rarelab BBS    (http://bbs.chem.pku.edu.cn)