Re: AMBER: Trajectory file ended and unit 24 error on open inptraj

From: Gustavo Seabra <>
Date: Sun, 16 Nov 2008 11:05:42 -0500

On Sat, Nov 15, 2008 at 10:33 AM, Siddharth Rastogi wrote:

> I have removed water from mdcrd file using ptraj.

Did you build a new prmtop file without the waters?

> $AMBERHOME/exe/sander -O -o SASA.out -p -c TY.crd -x
> TY.mdcrd

This input line is missing a '-i' before (although it may just
have been a typo)

> if in the above line if I use -x TY.mdcrd :The error is : Unit 24 Error on
> OPEN: inptraj

That's because you did not give it an inptraj file...

> if I use -y TY.mdcrd : There is no error but under results I have the
> following :Post processing of trajectory energies and Trajectory file ended

That may be because of the prmtop file. As I mentioned earlier (and so
did Carlos) when you remove the waters did you also create a new
prmtop file, without the waters? Also, the inpcrd file should be
without the waters (in your case, this is the TY.crd file). Assuming
you have all the files correctly (no waters), the syntax:

$AMBERHOME/exe/sander -O -p prmtop -i mdin -c inpcrd -o mdout -y inptraj

should work fine.

Gustavo Seabra
Postdoctoral Associate
Quantum Theory Project - University of Florida
Gainesville - Florida - USA
The AMBER Mail Reflector
To post, send mail to
To unsubscribe, send "unsubscribe amber" (in the *body* of the email)
Received on Fri Dec 05 2008 - 14:56:58 PST
Custom Search