[gmx-users] High Temprature MD with scaled params

[chris.neale at utoronto.ca]

I suspect that you need to re-equilibrate your box volume to the new  
solute parameters -- the volume probably needs to increase. Run a  
simulation with a much smaller timestep and the Berendsen barostat and  
the SD integrator. If this is stable, then use the output coordinates  
of that to start your simulation with your desired parameters.

-- original message --

Hi,

I have scaled the non-bonded parameters(charges and epsilon) of tip3p atoms
in ffnonbonded.itp file(charmm forcefield). They are scaled by a ratio of
3/5. The simulation is then run at 500K for the protein water system. The
temperature exploded after first 20 steps. This does not happen if I run the
simulations with the unscaled parameters. I have also tried this with T=400
and temperature remains stable.

Pooja

-- 
Quaerendo Invenietis-Seek and you shall discover.