[gmx-users] PMF in inhomogeneous fluid phase

[Andreas Mecklenfeld]

Dear Gromacs-users,

I have a question that may not be directly Gromacs-related. I want to 
calculate the potential of mean force (PMF) for a solute that is pulled 
away from a crystal surface. The issue is that the fluid phase is 
inhomogeneous, as it consists of water and cluster-forming ions. From my 
understanding, this would make the PMF calculation not only dependent on 
the pull-coordinate (z-axis of the simulation box), but the PMF would be 
also influenced by the position of the clusters which might change their 
position randomly in different umbrella windows. One could restrain the 
positions of the ions to freeze the local composition. However, this 
would be an enormous interference into the system and I'm not really 
comfortable in doing so.

Any suggestions would be highly appreciated.

Bests,
Andreas

-- 
M. Sc. Andreas Mecklenfeld
Technische Universität Braunschweig
Institut für Thermodynamik
Hans-Sommer-Straße 5
38106 Braunschweig
Deutschland / Germany

Tel: +49 (0)531 391-2634
      +49 (0)531 391-65685
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https://www.tu-braunschweig.de/ift
https://www.tu-braunschweig.de/ift/agmolth