Are you running constant pressure?  If so, not surprising the box is shrinking, 
since it is a vacuum.  You should use constant volume.

Also, you cannot change the values of those settings you have within the .mdp 
unless you have a good reason to and/or it is allowable by the forcefield.  
These have particular values as defined by the forcefield, and you need to use 
those.

Catch ya,

Dr. Dallas Warren
Medicinal Chemistry and Drug Action
Monash Institute of Pharmaceutical Sciences, Monash University
381 Royal Parade, Parkville VIC 3010
dallas.war...@monash.edu
+61 3 9903 9304
---------------------------------
When the only tool you own is a hammer, every problem begins to resemble a nail.

From: gmx-users-boun...@gromacs.org [mailto:gmx-users-boun...@gromacs.org] On 
Behalf Of Anik Sen
Sent: Monday, 7 May 2012 2:55 PM
To: gmx-users@gromacs.org
Subject: [gmx-users] Cut off problem

Dear Gromacs users,

I am using GROMACS 3.3.2. I have a problem in setting the cut off of my MD-run.
I want to see the interaction between some small atoms keeping them inside a 
periodic box without adding any solvent; i.e interaction between the atoms in 
the vacuum.
I have a total of 18-25 atoms in my system. The initial minimization was ok, 
but in case of the MD run, the job is failing after a few steps with the error,
Fatal error:
"One of the box vectors has become shorter than twice the cut off length or one 
of the box diagonal element has become smaller than cut off".
I have already changed the 'd' and 'rlist'; rvdw' and rcoulomb' to a number of 
different values to overcome the problem, but the problem persists.
How can I overcome this problem.

Thanking you in advance
Anik Sen
========================================================
Anik Sen
Student
CSIR-Central Salt & Marine Chemicals Research Institute,
Gijubhai Badheka Marg.
Bhavnagar, Gujarat 364002
[Image removed by sender. www.csmcri.org]
========================================================

<<inline: ~WRD000.jpg>>

-- 
gmx-users mailing list    gmx-users@gromacs.org
http://lists.gromacs.org/mailman/listinfo/gmx-users
Please search the archive at 
http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
Please don't post (un)subscribe requests to the list. Use the 
www interface or send it to gmx-users-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

Reply via email to