AMBER Archive (2002)

Subject: Re: Import of CHARMM force field and GB potential parameters into Amber7

From: David Case (case_at_scripps.edu)
Date: Mon Aug 05 2002 - 00:25:28 CDT

On Mon, Aug 05, 2002, Soonmin Jang wrote:
>
> I know that Amber7 unofficially support importing of CHARMM force field.
> I wonder if Amber7 can import CHARMM GB(generalied Born) parmaters also.
> If so, can I use not only CHARMM 22 (all atom model) but also CHARMM 19 (
> partially united atom model) and its GB parameters ?

No. The functional form of (most? all?) of the CHARMM GB parameterizations
is different from that used by Amber. So it is more than just importing
parameters; one would need lots of code modifcations.

Also, note that Amber does *not* support (yet?) CHARMM force fields. There
have been various partial efforts along these lines over the years, but none
were every completed. We have distributed some files that could help
someone get started in this direction, in the hopes that someone would "pick
up the ball" and finish the task. As far as I know, no one has done so.

Improved ability to work with CHARMM potentials is certainly on the "to-do"
list for the next release, but there are no guarantees. It seems pretty
unlikely that we will be able to implement CHARMM GB models anytime soon.

...dac 

-- 

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David A. Case                     |  e-mail:      case_at_scripps.edu
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