[gmx-users] Occupancy for a distance cut off

[ram bio]

Dear Gromacs Users,

I have a run a MD simulation on protein bound with ligand and ions
using Gromacs 4.5.4. I am able to calculate the distances between ions
and coordinating residues using g_dist. The output is in the form of
xvg file, but I am looking for the occupancy for a cut off distance
(3.5 Å) between ion and a particular residue atom during simulation.
Please suggest.

Thanks,
Pramod