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[Konstantin Rushchanskii <Konstantin.Rushchanskii@physik.uni-regensburg.de>]

Dear Bohdan,

I suppose, you have to pay attention to the following parameters:

1.) nstep can be too small to reach convergency for your system (50 is 
too small for so large systems).
2.) why do you use tsmear? If the compound is semiconducting, it is not 
neccessary.
3.) How many k-points do you use? You should use the nkpt variable 
instead of nqpt, or try to use ngkpt for setiing the MP mesh properly.
4.) Which kind of PSP's do you use? For atoms like H, O, C you need VERY 
large Ecut value. May be 80 Ha is not enough?
5.) Try to use iscf 5 (can be more stable and faster)


You can also try to use a different kind of PSP.
Hope this helps.

Sincerely,
Konstantin


Bohdan Andriyevsky wrote:

> Dear Abinit Users,
> My crystal, (HN2CH2COOH)2HNO3, has 50 atoms in unit cell, and I can't reach
> convergence of total energy in the SCF calculations.
>
> # DGN - conductivity
> enunit 2
> prtvol 1
> # - Parameters governing the convergence
> ecut   80.
> nband 168
> occopt 1
> tsmear 0.0002
> # - Options for the choice of calculations
> ixc   7
> nstep 50
> # SC run
> iscf1   3
> toldfe1 1.d-10
> nqpt1   0
> prtden1 1
>
> Please advise me the appropriate parameters of input file to reach the
> convergence of total energy.
>
> Regards,
> Bohdan Andriyevsky
>
>
>  


--
K.Rushchanskii, Dr.
Theoretische Physik, Universität Regensburg
93040 Regensburg Germany
tel: +49 (0) 941-943-2466  fax: +49 (0) 941-943-4382