[CP2K:2044] Re: optimisation problem of F compound

[Fawzi Mohamed]

On 24-apr-09, at 09:15, Fawzi Mohamed wrote:

>
> Hi Jörg,
>
> On 24-apr-09, at 01:39, Jörg Saßmannshausen wrote:
>
>> Dear Axel,
>>
>> yep, there are plenty in the BASIS_MOLOPT.
>> However, I was not sure if they are suitable for my problem, hence I
>> did not
>> use them. However, I will give it a try.
>
> I don't think that the problem with imaginary frequency is due to the
> basis set, that said the MOLOPT basis set is normally a good choice :)

as I said before I would try on a small system with F, like HF with  
increasing the cutoff until the MD conserves the energy well enough  
(you don't need long trajectories, just like 100 steps).

A p function with exponent X is *much* more difficult to represent on  
a grid than an s function with the same exponent, so you need an  
higher cutoff

ciao

Fawzi