AMBER Archive (2009)

Subject: Re: [AMBER] problem in pressure equillibration

From: David A. Case (case_at_biomaps.rutgers.edu)
Date: Tue Jun 16 2009 - 06:56:34 CDT

On Mon, Jun 15, 2009, wong105_at_llnl.gov wrote:
>
> I'm using amber 8 to equilibrate a 43286 atom system. After heating
> the system to 300
> K, 25ps (1fs timesteps, ntt=3) of NVT simulation followed (also at
> 300K). When I start
> the pressure equillibration, I get the following error:
>
> ASSERTion 'xtindex <= 10 .and. xtindex >= 0' failed in ew_direct.f at
> line 943.

I don't ever remember seeing this error before....Generally, you input looks
fine to me, except for this:

> cut = 11,

This is larger than is needed, and might(?) be related to the error, which is
in the nonbond list generation. Try running with the default value of 8.0,
and see if that makes a difference.

Another thing to try is to use pmemd rather than sander.

...good luck...dac 

-- 

================================================================
David A. Case                     | email:                      
BioMaPS Institute and Dept. of    |     case_at_biomaps.rutgers.edu
    Chemistry & Chemical Biology  |    fax:      +1-732-445-5958
Rutgers University                |    phone:    +1-732-445-5885
610 Taylor Rd.                    |                             
Piscataway, NJ 08854-8087   USA   | http://casegroup.rutgers.edu
================================================================

_______________________________________________
AMBER mailing list
AMBER_at_ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber