Just a heads up - If you want to convert the CHARMM parameters to AMBER, there are
slight differences between these two force fields (even though the functions
representing the potential energy looks alike). If I am not mistaken, the E_vdw and
E_dihedral terms are a little bit different.
> Francesco,
>
>> So I guess I can use the avalaible CHARMM parameters.
>
> I would test and demonstrate that these CHARMM parameters work in
> association with the Amber FF you wish to use.
>
>>>> I've been running GAMESS-US, both as stand-alone and RED-server, but it
>>>> fails to converge both with or without geometry optimization.
>>>
>>> When? at the first optimization step?
>>
>> Yes, it stops at the first stage, but I guess the problem cames from
>> bad charge-multiplicity couple I gave.
>
> - If you provide a bad multiplicity value or a bad charge value the QC
> code will crash reporting something like 'the number of electrons and
> spin multiplicity provided are not compatible'
>
> - If you have a problem of SCF convergence this likely means that your
> input structure is bad or that the wavefunction cannot be determined
> for the spin multiplicity chosen.
>
>> I submitted a new run using Gaussian 2009 with the RESP-X1 (B3LYP/6-31*)
>> charge model.
>> I will report the outcome on the mailing list....
>
> If you want to test another QM theory level, just ask us: we do want
> to implement _user defined options_ in R.E.D. Server Development. We
> can easily create a specific submission procedure to your problem.
>
> regards, Francois
>
>
>
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Tue Nov 01 2011 - 04:30:06 PDT
