Despite the vast economic interest it attracts, precious metal transport through hydrothermal fluids is still not well understood, and crucially depends on the species present in solution. In this thesis, we use ab initio molecular dynamics to study the solvation of gold and silver as monovalent ions. After studying the correction of dispersion forces necessary to model water, the most common geological solvent, we have dedicated ourselves to modelling of hydrothermal fluids, gradually increasing the system's complexity. Thus, we could characterise H2O/CO2 systems in supercritical conditions, identify new complexes and interpret experimental EXAFS signals by studying gold hydrosulphide and silver chloride complexes; and finally observe how CO2 influences the solvation of our metallic ions.
