Re: scnb value to prevent VDWs scaling

From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Mon Sep 10 2012 - 08:33:05 CDT

On Mon, Sep 10, 2012 at 3:28 PM, Marc Gordon <marcgrdn55_at_gmail.com> wrote:
> Hi Axel thanks for the prompt response.
>
>
> On Mon, Sep 10, 2012 at 3:02 PM, Axel Kohlmeyer <akohlmey_at_gmail.com> wrote:
>
>> On Mon, Sep 10, 2012 at 2:56 PM, Marc Gordon <marcgrdn55_at_gmail.com> wrote:
>> > Hi Axel
>> >
>> > The NAMD documentation for sure mentions scnb but as I said it doesn't
>> > explicitly say that an scnb value of 1 results in no scaling. Just that
>> the
>> > vdws interactions are divided by the scnb values.
>>
>> for AMBER inputs.
>>
>> [...]
>>
>
> Wait... for AMBER inputs?
>
> So scnb is not even considered unless the 'amber' option is set to 'yes'?
> .. so it is defaulted to 1 with charmm inputs?

yes. 1-4 LJ interactions for CHARMM are not scaled.
there are a limited number of atom types that have
modified epsilon and sigma for 14 interactions.
those are explicitly listed in the CHARMM parameter file.

axel.

-- 
Dr. Axel Kohlmeyer  akohlmey_at_gmail.com  http://goo.gl/1wk0
International Centre for Theoretical Physics, Trieste. Italy.

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