[CP2K:1723] Re: Some minor issues

Ondrej Marsalek ondrej.... at gmail.com
Mon Jan 26 15:34:59 CET 2009


Dear Teo,

On Mon, Jan 26, 2009 at 11:53, Teodoro Laino <teodor... at gmail.com> wrote:
>
> Dear Ondrej,
> point (1) and (2) have been fixed.

hopefully it will save someone some digging.

> Point (3) has been fixed as well in this way:
> -) for ghost atoms you don't need to specify any pseudo. This was just
> an overhead in the input since internally
>    those information were not used. Thanks for reporting this annoying
> problem.
> -) vdw correction for ghost has been disabled (early this morning,
> independently from these fixes).

This is good.

> -) You need still to define the element. This was a choice made some
> time ago. It may look like unhappy in cases
> like this one or in classical MD runs (since even there you don't need
> to know the element.. you only need the kind).
> Element information are anyway used in quite few places, so we preferred
> some time ago, to have always the
> full element specification for each KIND. This applies as well to ghost
> atoms.

And this is not a problem, if it's the last thing that is left.

Thanks for the fixes,
Ondrej


> Thanks again.
> Teo
>
> Ondrej Marsalek wrote:
>> Hi everyone,
>>
>> I have some minor issues with CP2K. Nothing too bad, but perhaps someone
>> would be interested.
>>
>> 1) In the manual, in the section
>>
>>    CP2K_INPUT / FORCE_EVAL / DFT / XC / VDW_POTENTIAL / PAIR_POTENTIAL
>>
>>    it says for the ATOMPARM keyword: "This required keyword can be
>>    repeated and it expects a list of words." However, a simulation runs
>>    just fine with defaults without a single ATOMPARM keyword.
>>
>> 2) Manual again, section
>>
>>    CP2K_INPUT / FORCE_EVAL / DFT / QS
>>
>>    EXTRAPOLATION_ORDER: "Order for the PS extrapolation..."
>>
>>    However, the setting is also relevant for the ASPC extrapolation.
>>    While this is strictly speaking also PS extrapolation (if I
>>    understand it correctly), it would probably be more clear if it
>>    referred directly to the EXTRAPOLATION setting (and therefore
>>    mentioned PS and ASPC).
>>
>> 3) Ghost atoms. It seems strange to me that you have to specify a
>>    pseudopotential and chemical element for a ghost atom. It
>>    specifically says at the GHOST keyword:
>>
>>    "This keyword makes all atoms of this kind ghost atoms, i.e. without
>>    pseudo or nuclear charge.Useful to just have the basis set at that
>>    position (BSSE calculations),or to have a non-interacting particle
>>    with BASIS_SET NONE"
>>
>>    So whatever you specify for pseudo and element gets (hopefully)
>>    ignored.  A somewhat bigger annoyance is ghost atoms seem to have a
>>    dispersion correction by default. Is this really the case? I
>>    certainly had to resort to the following ugly hack: specify an
>>    element that is not present in my system for the ghost atoms and then
>>    set the dispersion parameters to zero for that element (using
>>    ATOMPARM). It seems to work, but it is not pretty.
>>
>> If any of the developers find this relevant, good. If any decide to
>> change stuff, great and thanks in advance. I am especially interested in
>> point 3), 1) and 2) are just details, but maybe useful for total
>> newcomers.
>>
>> Best,
>> Ondrej
>>
>> >
>>
>
>
> >
>



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