[gmx-users] oplsaa vs. charmm

Justin A. Lemkul jalemkul at vt.edu
Fri May 27 17:54:18 CEST 2011

simon sham wrote:
> Hi,
> I have recently done two simulations on a protein at high temperature 
> near its melting temperature. At the beginning I used CHARMM forcefield, 
> and then OPLSAA to double check the results. There are some differences 
> in the structures between the forcefield used.  I know different 
> forcefields can give different results. All parameters in the 
> simulations were the same except the forcefield. Is there anyway I can 
> tell which forcefield gives more reliable results?

Compare with experimental results.  Without something to compare to, each is 
just a prediction of some unknown phenomenon.  Keep in mind that a single 
trajectory for either is not necessarily conclusive of anything.  Replicates and 
good sampling will be more informative.



Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080


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