[Pw_forum] What does this Warning mean?

[Stefano de Gironcoli]

Sergey Lisenkov wrote:

>     Warning: ef =  3.394168 is above the highest band at k-point 425
>              e  =   1.395595
>
>     Warning: ef =  3.394168 is above the highest band at k-point 443
>              e  =   1.685875
>
>     total cpu time spent up to now is    659.15 secs
>
>     total energy              =   -51.58489386 ryd
>     estimated scf accuracy    <    19.91060074 ryd
>
>     iteration #  9     ecut=    20.00 ryd     beta=0.10
>     Conjugate-gradient style diagonalization
>     ethr =  1.00E-02,  avg # of iterations =  3.0
>
>     total cpu time spent up to now is    720.68 secs
>
>     total energy              =   -51.23301401 ryd
>     estimated scf accuracy    <    20.58241637 ryd
>
>     iteration # 10     ecut=    20.00 ryd     beta=0.10
>     Conjugate-gradient style diagonalization
>     ethr =  1.00E-02,  avg # of iterations =  3.1
>
>....
>
>Have I to pay attention to this message?
>
>  
>
yes.

The warning means what it says.

You are doing a metallic calculation with a certain number of bands but 
for some k-points the Fermi energy happens to be higher that the highest 
computed band  therefore it is likely  that some additional bands, that 
you are not computing, should be taken into account  for those points.
Increasing nbnd should make the warning disappear.

Stefano de Gironcoli