Subject: CHARMM/SHAKE problem

From: Troy Wymore <[email-masked]>
Date: Fri, 19 Jun 1998 12:17:21 -0500 (CDT)

CHARMM people,

I am having a problem minimizing or running dynamics using CHARMM version
25b2 on NCSA's Power Challenge Array.  When running the same job using
CHARMM version 24b2 on our university's  Power Challenge, everything works
fine.  At NCSA I was having problems with the SHAKE constraints on the
bonds to hydrogen.  Looking at the starting coordinates, showed that all
bonds to hydrogen were of reasonable bond lengths, due to an earlier
minimization on our own computer.  Currently I am trying to minimize this
system at NCSA and SHAKE has not failed this time, but the energy of the
system is extremely high, though the starting coordinates come from a
converged ABNR minimization done on our own computer.

Are there some new parameters that need to be specified using the new
version of CHARMM with regards to SHAKE?

My SHAKE command is : shake bonh tol 1.0e-07 para
I am also using crystal to define the PBCs.
The system is a solvated lipid aggregate.

Any help would be much appreciated.

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Troy Wymore
Department of Chemistry
University of Missouri-Columbia
Columbia, MO 65211

e-mail: [email-masked]
http://www.missouri.edu/~chemtw/troy.html
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