[gmx-users] About Temperature coupling and Energy Transfer....
jalemkul at vt.edu
Tue Nov 20 23:47:37 CET 2012
On 11/20/12 5:42 PM, jhon michael espinosa duran wrote:
> Hi all.
> I am trying to simulate a protein initially at 0K
> in water at 310K. I couple the water to 310K with
> tc=0.5 and the Protein is decouple tc=-1.
> The idea is analyze how is the transfer of energy from the
> water to the protein.
> The interesting thing is that after 200ps the temperature of the
> water is constant (obviously) at 310K and the temperature of the protein
> goes up 628K!!!!!!
> I test the same system for different water temperatures 100K, 150K and 200K
> and the protein temperature always goes up 400K, 475K and 525K, respectively
> Can some one give an explanation?
It's because you have tau_t set to -1. That tells mdrun not to control the
temperature of the protein. You've got warm solvent around a cold protein with
an unregulated temperature, so the system is rapidly transferring heat into the
protein and mdrun believes that's normal.
Justin A. Lemkul, Ph.D.
Department of Biochemistry
jalemkul[at]vt.edu | (540) 231-9080
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