[CP2K:1521] Re: CHARMM params

Laino Teodoro teodor... at gmail.com
Wed Nov 5 06:26:15 UTC 2008


Hi Ilya,

The issue could be in the way the UB interactions are treated. It  
could easily be that there's
some kind of mismatching in the way we treat them compared to NAMD or  
CHARMM.

I don't think the problem is in the PSF, but just to be totally sure:

1) did you try to run NAMD using the same PSF you use for CP2K?
      (if not please do it.. just to be sure of possible  
inconsistencies)

2) why don't you try to discover  the source of that "-" ?
      once it is clear I'm more than happy to bug fix (in case of  
possible bugs) CP2K.
      normally "-" signs are there for strange conventions. At least  
in AMBER top file
      the "-" is used as a kind of hack to change completely the  
definition of some part of
      forcefield.

Will wait for your follow up. As usual, thanks again for your  
contribution.
Cheers
Teo

On 4 Nov 2008, at 23:57, Axel wrote:

>
>
>
> On Nov 4, 4:23 pm, Luca <bellu... at unisi.it> wrote:
>> Hi ilya,
>> did you make file.psf with psfgen?
>> In this case I suggest to use  FORCE_EVAL / SUBSYS / TOPOLOGY /  
>> GENERATE
>
> no, i consider this a bad idea. the integrated topology builder
> can never be as powerful as psfgen or the charmm tools.
>
> it would probably best to generate a (very) small test case
> and try to track down what the _real_ culprit is.
>
> cp2k should be able to handle correct psf files. so
> it needs to be validated whether the psf file is broken,
> or the psf parser, or psfgen, or the parameter files.
>
> cheers,
>      axel.
>
>> section to make your psf  consistent with cp2k. (see manual)
>> Can you attach your input files?
>>
>> Luca
> >




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