Dear dac + others
What I mean by a "blow out" is that the system has a propensity towards
suddenly developing enormous energies from which there is no recovery.
I have been using ntc = 2 (shake ON).
Any other possibilities?
Many thanks
Hayden
I have recently created a phosphorylated sugar residue using gaussian and
resp procedures. The molecule was successfully created and made into a prep
file. I checked this molecule within leap and it gave no error readings once
I had specified all the connect atoms.
I have run dynamics on the molecule beginning at 0 K with high coupling to
the heat bath (ntt=1) and gradually relaxed the restraints on the molecule
over time. Once it was producing steady dynamics I removed the restraints
and performed ordinary dynamics at 300K for 300 picoseconds. I then took
this structure and minimized it to produce my final structure. However, the
problem is that if I run dynamics on this minimized construct at higher
temperatures (say 350 K) I get blow outs. Therefore my questions are:
1. Does my construct require further equilibration? (Surely not - I;ve
done approximately 3 nanoseconds.)
2. If not, is there something more severely wrong with my molecule?
Perhaps an error in the gaff parameters for certain connectivities within my
construct? I've made other sugars that do not suffer from this problem.
3. Are saccharide moieties like this more prone to blow outs than
proteins?
Many thanks in advance
Hayden
______________________________________________
Hayden Eastwood
Perdita Barran Research Group
Joseph Black Building
Edinburgh University
West Mains Road
EH9 3JJ
Tel: 0131 650 4773
e-mail: s0237717.sms.ed.ac.uk
Research page:
http://homepages.ed.ac.uk/pbarran/PBRG/
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
Received on Thu Nov 24 2005 - 14:53:01 PST
