Through molecular level computer simulation, we “measure” the PVT properties, chemical potential, immiscibility, phase equilibrium, enthalpy, solvation structure, diffusion, metal-ion association and transport properties of geological fluids (H2O, CO2, CH4, N2, H2S, O2, HCl, NaCl, CaCl2, KCl, ore-forming metal ions and their mixtures) , with an ambitious plan to extend the experimental temperature and pressure range from less than 1000K and 10,000 atm to 2500K and 100,000 atm.

Most of these properties are traditionally measured by experiment, but those experiments are usually limited in a small temperature-pressure-composition (PTX) range because of experimental difficulties and expenses. So far tens of thousands of experimental data about geological fluids and minerals have been reported, but they are mostly limited below 5000atm and 1273K. With the molecular level computer simulation, now it is possible for us to predict the above-mentioned properties up to 2500K and 100,000atm.

Equations of state are mathematical functions of temperature, pressure, volume and composition. From equations of state, one can derive PVT properties, fugacities, chemical potentials, activities, phase equilibria, immiscibility, gas solubilities, enthalpy, etc. With our efforts in the past and our continuing effort in the future, we develop accurate equations of state for H2O、CO2、CH4、N2、H2S、C2H6、O2、H2、NaCl、CaCl2 and their mixtures. Now we are ambitiously constructing a large database and a computer software package, allowing the geochemists and chemists to calculate various properties online over a large temperature-pressure range.

Based on ab initio quantum caclculations, we develop complicated angel-dependent molecular potentials. From these potentials, we predict the physical and chemical properties of fluids and minerals in geological environments. Our recent progress demonstrates the great opportunity and potential in this research area, allowing geochemistry to accrue in a new dimention. As examples, the stability of methane hydrate is accurately predicted using this method and the thermodynamic properties of CO2-H2O mixtures are reproduced even under the highest experimental temperature-pressure conditions.

Apply our theoretical developments (molecular simulation, equation of state, ab initio calculation) to the geochemical studies( fluid inclusions, rock-fluid interactions, gas hydrate, CO2 sequestration, oil-gas formation and migration, ore mineral formation, etc.), quantifying physico-chemical processes in and between different spheres or reservoirs in the Earth’s surface and deep in the crust and mantle.