Updating the estimated assemblage of stable phases in a Gibbs energy minimizer

Several numerical strategies are presented that can be used to effectively and efficiently update the estimated assemblage of stable phases in a Gibbs energy minimizer. Decisions must be made in selecting which phase should be added to or withdrawn from the system, the order in which certain combinations should be considered, testing procedures of the appropriateness of a candidate system for further consideration, etc. The manner in which these methods are performed have a profound effect on the performance and reliability of such calculations; without effective strategies, the solution may not converge. While these matters are somewhat straightforward for relatively small systems, far greater challenges are experienced in large systems containing many chemical elements. These matters will be discussed and effective solutions that have been integrated into thermochimica throughout the course of its development will be presented.