Francois,
Il 01/11/2011 12:19, FyD ha scritto:
> 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.
You are right, I am planning to run short NVE simulations to observe if
energy drift occur.
Do you have any better suggestion that can help me to test the method's
effectiveness?
>
>>>> 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.
This is the most frequent problem, but before I used to submit job with
method not belonging
to DFT familiy. Now I submitted the job using GAUSSIAN with a DFT method.
The input geometry I am using cames from the X-ray structure. I hope
this is good enough.
If the computations will fail again, I will try to minimize the
structure with sybyl or a generic software.
>
>> 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.
Regarding this option, thank you for the willingness. I wanna wait for
the response of the already implemented options.
What I think is that, as general suggestion, you should implement some
option that skipping geometry optimization calculating
electrostatic potential directly on the user-supplied structure.
> regards, Francois
>
>
>
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Received on Tue Nov 01 2011 - 05:30:05 PDT
