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[matthieu verstraete <matthieu.jean.verstraete@gmail.com>]

Hello Daojian,

you might also try

iprcel 45

as your system has quite anisotropic screening properties. The H
termination is not necessarily physical (is H saturated Ni common
experimentally?) but saturating the back side of the slab can be
meaningful if it localizes the wavefunctions better (less extent into
the vacuum for the "artificial" side of the slab).

Matthieu

On Fri, Jun 26, 2009 at 10:04 AM, Cheng Daojian<chengdaojian@gmail.com> wrote:
> Dear Dr. Pierre-Matthieu Anglade,
>
> Thanks for your help.
> I have used your setting. It seems that the energy of the free Ni surface 
> can converge. However, the system of a single carbon on the same surface 
> didnot converge. What should I do? Is it useful to saturate one of the 
> surface with hydrogen?
>
> Best wishes,
> Cheng Daojian
> chengdaojian@gmail.com
> 2009-06-26
> ----------------------------------------
> Physique des Solides Irradiés et des Nanostructures,
> CP234, Université Libre de Bruxelles
> Bd Du Triomphe, B-1050 Bruxelles, Belgium
> ----------------------------------------
> ============ 2009-06-25 15:08:23 ============
>>Hi,
>>
>>The difficult convergence may be due to the fact you now have :
>>surface + spin + metal...
>>You could try various mix of the following :
>>diemac  100
>>diemix  0.2
>>nline  16
>>npulayit  30
>>nstep  100
>>Hopefully it will help.
>>
>>regards
>>
>>PMA
>>
>>On Thu, Jun 25, 2009 at 12:55 PM, <chengdaojian@gmail.com> wrote:
>>> Dear All Users,
>>>
>>> I try to understand the adsorption of the single carbon on Ni(111) 
>>> surface. I
>>> used spin-polarized calculations and PAW pseudopotentials. The PAW
>>> pseudopotentials come from the Abinit.org web (Ni.atompaw.gga.paw and
>>> C-GGA-uspp.paw). I can get the accurate Ni lattice constant. PBE gives a 
>>> value
>>> of 3.52 A, which concides with the experimental value.
>>>
>>> Then I try to study the adsorption of the single carbon on Ni(111) 
>>> surface as
>>> follows. It seems it doesnot work, and the energy doesnot converge. 
>>> Please find
>>> the input as follows.
>>>
>>> rprim
>>>  1.41421356  .0000000  .000000
>>>  -0.70710678 1.2247448  .000000
>>>   .000000    .000000  5.1961524
>>>
>>> occopt 7
>>> tsmear 0.01
>>> kptopt 1          # Option for the automatic generation of k points, 
>>> taking
>>>
>>> #Definition of the atom types
>>> ntypat 2          # There is only one type of atom
>>> znucl 28 6         # The keyword "znucl" refers to the atomic number of 
>>> the
>>>                  # to the type(s) of atom. Here, the only type is Aluminum
>>> ngkpt  4 4 1
>>> nshiftk 1
>>> shiftk  0.5 0.5 0.5
>>>
>>> #Definition of the unit cell
>>> acell 3*6.6567
>>> chkprim = 0
>>>
>>> #Definition of the atoms
>>> natom 21        # Three atoms per cell: three aluminum layers and some 
>>> vacuum
>>> typat 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2    # These atoms are of 
>>> type 1,
>>> that is, Aluminum
>>> xred
>>>   .00000000   .00000000   .00000000
>>>   .50000000   .00000000   .00000000
>>>   .00000000   .50000000   .00000000
>>>   .50000000   .50000000   .00000000
>>>   .33333333   .16666667   .11111111
>>>   .83333333   .16666667   .11111111
>>>   .33333333   .66666667   .11111111
>>>   .83333333   .66666667   .11111111
>>>   .16666667   .33333333   .22222222
>>>   .66666667   .33333333   .22222222
>>>   .16666667   .83333333   .22222222
>>>   .66666667   .83333333   .22222222
>>>   .00000111   .00000111   .33333333
>>>   .50000111   .00000111   .33333333
>>>   .00000111   .50000111   .33333333
>>>   .50000111   .50000111   .33333333
>>>   .33333111   .16666167   .44444444
>>>   .83333111   .16666167   .44444444
>>>   .33333111   .66666167   .44444444
>>>   .83333111   .66666167   .44444444
>>>   .00000111   .50000111   .55555555
>>> natfix 12
>>> iatfix 1 2 3 4 5 6 7 8 9 10 11 12
>>>
>>> #The relaxation
>>> ionmov 3
>>> tolmxf 5.0d-4
>>> ntime 200
>>>
>>> #Exchange-correlation functional
>>> #ixc 11            # LDA Teter Pade parametrization
>>> ecut 26         # Maximal kinetic energy cut-off, in Hartree
>>>
>>> pawecutdg 50.
>>> getwfk -1
>>> prteig 0 prtden 0
>>> optforces 2
>>>
>>> nsppol 2
>>> spinat 0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 4
>>>       0.0 0.0 0
>>> #Definition of the SCF procedure
>>> nstep 50          # Maximal number of SCF cycles
>>> toldfe 1.0d-6
>>>
>>> I hope you can give me some advice.
>>>
>>> Thank you very much.
>>>
>>> Best wishes,
>>> Cheng Daojian
>>> chengdaojian@gmail.com
>>> 2009-05-26
>>> ----------------------------------------
>>> Address: Physique des Solides Irradiés et des Nanostructures,
>>> CP234, Université Libre de Bruxelles, Bd Du Triomphe, B-1050 Bruxelles,
>>> Belgium
>>> tel +32-2-650.57.36, fax +32-2-650.52.27
>>> E-mail: chengdaojian@gmail.com; dcheng@ulb.ac.be
>>> Office: Campus de la Plaine, Bat. NO, niveau 3
>>> CP234, Université Libre de Bruxelles, Bd Du Triomphe, B-1050 Bruxelles,
>>> Belgium
>>> ----------------------------------------
>>>
>>>
>>
>>
>>
>>--
>>Pierre-Matthieu Anglade
>>
>
> = = = = = = = = = = = = = = = = = = = =
>
>
>
>



-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr. Matthieu Verstraete

European Theoretical Spectroscopy Facility (ETSF)
Dpto. Fisica de Materiales,
U. del Pais Vasco,
Centro Joxe Mari Korta, Av. de Tolosa, 72,   Phone: +34-943018393
E-20018 Donostia-San Sebastian, Spain        Fax  : +34-943018390

Mail : matthieu.jean.verstraete@gmail.com
http://www-users.york.ac.uk/~mjv500