The thermochemistry library Thermochimica

Progress in numerical methods in computing thermodynamic equilibria is presented that is particularly well suited to large multicomponent multiphase systems and is incorporated in the thermochemistry library Thermochimica. The method described in this paper exploits fundamental principles of equilibrium thermodynamics that results in simplifying the numerical approach. The chemical potentials of all species and phases are defined by the chemical potentials of the component elements and the objective is to systematically partition the Gibbs energy of the system in a manner that diminishes the residuals of the mass balance equations. Several numerical advantages are obtained through this simplification that improve the rate of convergence while simultaneously promoting numerical stability. The resulting software library Thermochimica is described with an overview of the numerical methods that it employs.

► Advancement in numerical methods in computing thermodynamic equilibria. ► Advancement in line search algorithms applied to thermodynamic calculations. ► A hybrid exact-/quasi-Newton approach is taken to solve non-linear equations. ► The software is capable of handling an unlimited number of elements, which is needed for nuclear fuel.