[Pw_forum] cannot bracket Ef error

[degironc]

W. YU wrote:

>Dear PW users,
>
>I have been doing a calculation on an
>antiferromagnetic system. The SCF job goes well. But I
>kept getting the following error message when I tried
>to do a band structure job: 
>  
>
you should not specify calculation='nscf' but calculation='bands' for
band structure run.

stefano

>=======================
>from efermig: error # 1
>internal error, cannot bracket Ef.
>===================================
>Note: I also got the "one eigenvalue not converged"
>warning many times before the final error for fermi
>energy locating if I use david diagonalization but
>conjugate gradient method suppress it.
>==================================================== 
>I have browsed this forum and found little information
>about this. I tried to change kpoint grid and mixing
>schem but it doesn't work. Prof. Paolo said there are
>some alternatives to the smearing technique. Do you
>mean "tetrahedra" or something elese. I think
>"tetrahedra" works only for dos calculation.
>
>Could anybody help me with this problem?
>
>The following is a link to my input file:
>
>http://www.geocities.com/yuwen_66/run_li2cuo2_band.htm
>
>Best regards,
>
>Wen YU
>
> 
>
>
> 
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