[CP2K:1981] counter charge

Teodoro Laino teodor... at gmail.com
Thu Apr 9 14:08:38 UTC 2009


Just a remark:

of course the energy of an isolated charged system is well defined.
It is not defined in case of a periodic charged system (without 
considering the
neutralizing background charge).

cheers,
Teo

Teodoro Laino wrote:
> Dear Jun,
>
> Just to avoid confusion, the neutralizing background charge is not 
> something  manually added  in CP2K because
> we don't like to have charged systems.. It comes out of the box from 
> the EWALD summations and there's
> nothing you can do to avoid it (the energy of a charged system would 
> terribly diverge!!!)...
> unless... unless your system is not charged..
>
> The answer to your question is : no, it is not possible. And even if 
> it would be possible, it may end up in problematic
> issues.
>
> Think about putting counterions, instead, in your simulation if you 
> don't like to have charged systems.
>
> Teo
>
> Jun wrote:
>> Hi all,
>>
>> I want to calculate a system with a net charge. I know cp2k will
>> automatically apply a homogeneous neutralizing background charge with
>> opposite sign in the simulation cell. Is it possible in cp2k to define
>> an area with any shape (e.g. sheet or slab) in which the counter
>> charge is evenly dispersed? Or any other way to do this?
>> Many thanks, and happy Easter holiday.
>>
>> Jun
>> >>
>>   
>




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