AMBER Archive (2006)

Subject: Re: AMBER: Could not find atom type.

From: David A. Case (
Date: Mon Apr 17 2006 - 11:40:05 CDT

On Mon, Apr 17, 2006, Sergey Krishtal wrote:
> Could you advise me please what to do in the following situation: I`m going
> to simulate CH2-group as a single site. I specified this group as C2. When I
> try to save prmtop and inpcrd files I get the following message: "Could not
> found type C2". However, leaprc.ff03 adds C2-type with sp3 hybridization.

We would need more details to know exactly what happened. But note that ff03
is an *all-atom* force field. Just because an atom is named "C2" does not
mean that you can use it to replace a CH2 group.

If you want a united atom force field, there is a new one in Amber 9, called

...good luck....dac

The AMBER Mail Reflector
To post, send mail to
To unsubscribe, send "unsubscribe amber" to