Dear All, I am looking for a program or CHARMM script to analize the most populated counterion positions around a biomolecule from a MD simulation. In (M.A.L. Eriksson, T. Hard and L. Nilsson, Biophysical Journal, 1995, 68, 402-426) a 3-d histogram density map was constructed from an analysis of the MD run. Is this program avalible? David R. Langley