Constraint failure in RATTLE again

From: li (
Date: Sat Nov 06 2004 - 20:13:26 CST

 Below is a nice solution to this problem here. 
"First of all make sure you do these things first:         [0] CHECK THAT YOUR DIHEDRALS/BOND ANGLES are defined in your .psf         file! ( I got this error "ERROR: Constraint failure in RATTLE         algorithm for atom " before and it was because of a screwed up         .psf)         [1] Minimize until 'gradient tolerance' is below 1 or so.         [2] Heat the system from O K to your temperature of interest         slowly. (e.g. I heat mine from 0K to 300 K over 300 000 ps )"
    For my system,when the time step was set to 1 fs, every run was ok. But after the time step was set to 2 fs,even when I had minimized it until gradient tolerance was  0.1 or so and equilibarted for a fairly long time with the time step set to 1 fs, this error still came out once in a while.
 Is there any other cause for this problem?-- USTC Alumni Email System
USTC Alumni Email System

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