[QE-users] error in turbo_lanczos step

[Oscar Baseggio]

Dear Mohamed,
you could try to run turbo_lanczos with

pseudo_hermitian =.false.

attention that it is twice slower.

best regards,
Oscar Baseggio


Il 2019-04-21 15:29 Mohamed Ahmed Abd-Elati ha scritto:
> Dear developers and users
> 
> I am trying to calculate absorption coefficient for graphene flake, I
> am faced the following error during turbo_lanczos step
> 
>      Lanczos iteration:     16   Pol:1
>      lr_apply_liouvillian:  applying interaction: normal
>      alpha(00000016)=  0.000000
>      Error: Beta is negative:     -0.180579895085004E+04
> 
>      !!!WARNING!!! The pseudo-Hermitian Lanczos algorithm is
> stopping...
> 
>      Try to use the non-Hermitian Lanczos algorithm.
> 
> Although, I am calculated all steps for Benzene without any problems.
> Also two files created named evc1_1.dat and evc1_2.dat
> 
> Thanks
> 
> MOHAMMED A. ABDELATI
> _Assistant Lecturer_
> Laser Applications in Metrology Photochemistry and Agriculture (LAMPA)
> Department, National Institute of Laser Enhanced Sciences (NILES),
> Cairo University, Giza, Egypt.
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> 
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