# Forcefield for studying a two phase system, consisting of noble gases and gaseous organic components

I am preparing to do a MD-simulation of a system which consists of two phases. The gaseous phase consists of $H_{2}$, $Ar$, $He$, $N_{2}$, $CH_{4}$ and $CO_{2}$. In this system, $p=0.355 ~bar$ and $T\approx 350 K$.

In direct contact with this phase is an aqueous phase, consisting of the same components and water.

I've spent some time looking in to suitable forcefields for this system, but to avoid making amateurish mistakes, I decided to ask this community for advice. Are you aware of any forcefield which would be suitable for this kind of simulation? I'm currently looking into Dreiding FF, and considering ReaxFF (although this is not the first choice, since it needs ab initio calculations to support it, and I don't really need data about reactions).

I'm using DL_POLY Classic, which has no forcefield of its own.

It looks like there may be a possible using ReaxFF to study the properties of multiphase in the same simulation system. This group just has being developed the ReaxFF which might suit your need. Dr. Adri Group Research Topics.

Also here is the study of MD simulation of containing gaseous and aqueous mixing phases. Molecular Modeling of Geometries, Charge Distributions, and Binding Energies of Small, Drug-Like Molecules Containing Nitrogen Heterocycles and Exocyclic Amino Groups in the Gas Phase and Aqueous Solution

Hope this guide you.