The ABINIT Users Mailing List ( CLOSED )

[Thierry Deutsch <thierry.deutsch@cea.fr>]

Hi,

       ABINIT can use periodic Poisson solver based on plane waves or 
Poisson solver for isolated system. The last one is based on wavelet 
(exactly interpolating scaling functions). If you use plane waves to 
represent wavefunctions, there is no difference for neutral systems.
In this case, the dependence of the kinetic term versus the size of the 
box is predominant (plane waves delocalize).

For charged system, (as H3O+), the Poisson solver based on wavelet is 
more accurate and uses very very less memory.

If you calculate NH3 and H3O+ together in a big box, you only need to 
specify the total charge. The system should localize an electron on H3O.
Because you have molecules, you should have 1 for occupied states 
(spin-polarized case).

An alternative is also to use the whole wavelet part of ABINIT... The 
advantage is to use less memory.

Best Regards,

Thierry


Quan Phung Manh a écrit :
> After calculating NH4+, I have more question.
> If I have a big box with a molecule NH3 and an ion H3O+ for example. 
> How can I simulate it? How can I sure that the charge + is in H3O, not 
> NH3? Can I solve this by using occ?
>
> Best regarded


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Thierry Deutsch                                                        
Laboratoire de simulation atomistique (L_Sim)
INAC/SP2M                                       Tél:(33) 04 38 78 34 06
C.E.A.Grenoble                                  Fax:(33) 04 38 78 51 97
17, Avenue des Martyrs                    mailto:Thierry.Deutsch@cea.fr
38054 GRENOBLE CEDEX 9 FRANCE                  http://inac.cea.fr/L_Sim
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