**Gibbs code** is a general Monte Carlo
simulation code. It has been developped jointly by
Université Paris Sud ,
CNRS
and IFPEN. The
Gibbs code is aimed at computing the equilibrium properties
of fluids by molecular simulation, using a Monte Carlo
method in cubic, parallepipedic or even non orthorhombic
simulation boxes.

**Main features **

- Determination of phase properties: statistical ensembles NVT, NPT, μVT. The NVT and μVT determinations may be done while imposing an external field defined on a grid. Among other applications, it allows to simulate the adsorption of molecules in microporous crystalline solids of cubic, orthorhombic or triclinic structre.
- Calculation of phase equilibria, either two-phase (L-V, L-L) or multiphase (L-L-V. . . ), using the Gibbs Ensemble at imposed pressure or imposed global volume.
- Calculation of fluid solubility in polymeric materials in the osmotic ensemble (semi-grand canonical).
- Calculation of chemical equilibria, using the Reaction Ensemble at imposed pressure or imposed volume, in either one-phase, two-phase or multiphase simulation. It is also possible to simulate a chemical equilibrium involving a pseudo-particle, as well as a virtual solid phase.
- Calculation of interfacial tensions.
- Calculation of vapour pressures and saturated properties of given-composition liquid mixtures in the Boiling Point Ensemble
- Thermodynamic integration

**Other specific features **

- Communication with other simulation codes
to account for quantum effects e.g.
**using Gaussian code** - Hanling united atoms forcefield, including the
**Anisotropic United Atoms model**. - Simulations using
**coarse grained potentials** - Optimized for multicore machines
with
**parallel programming**using both MPI and OpenMP librairies.