Monte Carlo calculations for pressure dissociation of H2

Abstract

A Monte Carlo method is proposed for the calculation of dissociation of diatomic homonuclear molecules as a function of temperature and density. The procedure is illustrated for hydrogen in the temperature range up to 15000 K. The essentially quantum mechanical processes of dissociation and binding are replaced here by a classical model system of free atoms and molecules whose numbers in the system may vary according to certain probabilistic rules. A choice must be made of the interaction potentials between particles, which are then replaced by equivalent hard−spheres repulsive interactions. The attractive part of the singlet H−H interaction, which is responsible for the bound state of two atoms, is replaced by an intrinsic ’’binding’’ energy attributed to each molecule present in the system. Results show that dissociation starts at densities well below the packing density of molecules.