AMBER Archive (2006)

Subject: RE: AMBER: vlimit exceeded for step 0, vmax = infinity

From: Yong Duan (
Date: Tue Nov 14 2006 - 17:05:08 CST

This is likely due to the short bonds between DH and H's. You may try
smaller time step, 0.5 fs or shorter.
Good luck!

-----Original Message-----
From: [] On Behalf Of
Sent: Tuesday, November 14, 2006 2:45 PM
Subject: Re: AMBER: vlimit exceeded for step 0, vmax = infinity

Hiya, amber users,
I have added some mass to the DH atom as Yong suggested, however, i still
have error messages when i started to run md, as follows:

     Coordinate resetting (SHAKE) cannot be accomplished,
     deviation is too large
     NITER, NIT, LL, I and J are : 0 5 65721215812159

     Note: This is usually a symptom of some deeper
     problem with the energetics of the system.

I dont quite understand what does it mean? and also the bond energy of 1st
step md is still differeent from the last step of the minimization.
Does anyone has any idea about this please?
Thanks very much.

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