[Wien] Isolated Atomic Calculation - Fermi Energy

[Stefaan Cottenier]

> below is data about 12th iteration   from *.scf file. Please could you 
> specify where is energy for 2s and for 2p band?

As this is a free atom, it's almost trivial. First look what the Fermi 
energy is:

> :FER  : F E R M I - ENERGY(TETRAH.M.)=  -0.21810


Hence, you have to look only at eigenvalues up to this energy :

>        K=   0.00000   0.00000   0.00000            1
> :RKM  : MATRIX SIZE  946LOs:   5  RKM= 4.99  WEIGHT= 1.00  PGR:   
>        EIGENVALUES ARE:
>         -1.9622774   -0.2180955   -0.1097737   -0.1097737   -0.1097737 

That means the -1.96 Ry is the 2s, and -0.218 is the 2p. From your 
output, it can be seen you did a  non-spin-polarized calculation (which 
is wrong!), then both eigenvalues are doubly occupied, and you do have 
indeed 2s^2 2p^2, with the 2p eigenvalue equal to the Fermi energy.

The FAQ clearly mentions that free atom calculations should be done 
spin-polarized (you will see this will lower the energy compared to your 
non-spin-polarized :ENE).

Stefaan


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