[gmx-users] Temperature dependence of virial of an initial configuration

[rakesh sharan]

Dear all, 

I have a question regarding computation of different components of virial of my starting initial configuration using Gromacs. When I am running job by setting nstep  = 0 (system is bulk spce water) to get potential energy and components of virial of my starting configuration, I am observing that output components of virial are strongly temperature dependent, even though potential energy is fixed. This is very surprising to me, as one would expect that both energy and virial of a starting configuration should be independent of temperature. I would highly appreciate any thought over this temperature dependent virial of my initial configuration. I would also appreciate very much if you could suggest any robust way to get the contribution of virial to the total pressure of a given configuration.

Thanks, 

Best, 
Rakesh
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