[gmx-users] Spatially resolved diffusion coefficient

[Jacob Alan Spooner]

Dear GROMACS users,

I am interested in obtaining a spatially resolved diffusion coefficient for water in a confined pore system consisting of a slab of metal and water.  My goal is to obtain the xy component of diffusion coefficient (parallel to the metal slab) as a function of distance away from the metal (z).  I am familiar with the ability to calculate D from the msd or the velocity acf in gromacs, but have never been interested in spatial dependence of D. A brief dive into the literature shows me that there are several methods for obtaining a distance dependent D from MD trajectories and these methods vary widely in complexity.  I am wondering if anybody has any experience/success with this type of calculation using GROMACS and could give some advice regarding the most useful tools/methods.

Best Wishes,
Jake Spooner