[CP2K:6557] Checking for a True Minima

[Florian Schiffmann]

Hi Olivia,

fi you don't add the counter ions you will have to set the Charge keyword 
in the DFT section as well. If you are dealing with a charged system you 
will not be able to perform cell optimizations as the stress tensor with a 
periodic charge is not defined as far as I know. So in that case you will 
have to switch to a normal GEO_OPT.

Cheers
Flo

On Friday, May 29, 2015 at 9:49:08 PM UTC+10, Olivia Lynes wrote:
>
> Hi Flo,
>
> Thanks for the clarification, I started with optimisations to get used to 
> CP2K input/output and timings for larger systems. I'm moving MD when I add 
> in the ions, I have a second question if you don't mind- If I'm adding in a 
> +2 ion is it just a case of adding the CORE_CORRECTION tag into my KIND 
> section for that atom?
>
>
> Thank you!
>
> Olivia 
>
> On Friday, May 29, 2015 at 7:52:41 AM UTC+1, Florian Schiffmann wrote:
>>
>> Hi,
>>
>> it might be that I misunderstand what you intend to do but for water 
>> boxes, i.e. a liquid, it is not meaningful to do optimizations. The 
>> energetic minimum should be the crystal or ice in your case. As liquids 
>> only exist at finite temperature you might have to sample using MD. 
>> If you are working with ice structures then normal mode analysis can be 
>> used just the way everbody else described
>>
>> Flo
>>
>>
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