[gmx-users] Surface tension calculation and counting number of interfacial molecules

[Siddhesh Kamat]

Hello everyone,


I am working on  a system comprising of two solvents (hexane and water) and
i have placed acid molecules ( from 0 to 40)  at the interface (NAPzT
ensemble). I have two questions:

1. The number of acid molecules at acid-water and acid-hexane may not
necessarily be the same. So how do I make sure that which one is in bulk
and which is at interface? I can get an approximate idea using density
profiles but what to do to get an exact count?

2. I need to calculate surface tension as a function of Z. gmx energy
provides a time average. What is the easiest option available?

Any suggestion will be highly appreciated.

Siddhesh Kamat
Graduate Student
Rutgers University