CHARMM Development Project
Hi.
I am trying to restrain the distance between two CA atoms (of the Go model) by using RESD command in charmm (using -custom) e.g.
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gorex.pl -n 500 -par initruns=100,equilruns=100 -dir gorex11 -temp 4:300:400 -log rex.log -charmmlog charm.log -elog energy.log -custom setup custom4.file -mdpar steps=1000,fbeta=10.0,timestep=0.02,dynoutfrq=100 -mdopt trajout 1E0Q
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where custom4.file is the custom file as below:
=========================================

* Custom Restraint
*

set atom1 PROT 1 CA
set atom2 PROT 17 CA

RESD KVAL 10 RVAL 6.6 IVAL 2 POSITIVE -
1.0 @atom1 @atom2 -

======================================================


here 1E0Q is a peptide go model that I obtained from the MMTSB server. By running the simulation I am getting following errors:
** ERROR IN SHAKEA ** DEVIATION IN SHAKE TOO LARGE


***** ERROR IN SHAKEA ***** COORDINATE RESETTING WAS NOT ACCOMPLISHED IN 500 ITERATIONS

Can someone please me with the troubleshooting.
Thanks & Regards
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