Ronald Lovett is supported by a grant from the Theoretical and Computational Chemistry Program to develop a strategy for calculating Third Law free energies of solids. A simulation approach that converts a solid continuously into an ideal gas provides the formalism for defining the free energy of a metastable and transitory structure. Analytical and computer simulations-based estimates for the free energies of solid structures using this definition will be used to predict the equilibrium structure of a solid, determine the accessibility of equilibrium structures, and calculate the rates of fundamental steps in the growth of solid structures. These techniques will also be used to estimate the surface free energy of solid-solid and solid-fluid interfaces. Properties of commercially important solid state materials depend on their structure. It is frequently the case that multiple solid state structures are possible, and to know which physical structures can be realized, one must be able to assign a free energy to all candidate structures. Furthermore, to know whether a particular structure can be realized by transformation from a liquid or another solid structure, one must also be able to assign free energies to intermediate, transitory structures. Lovett's research is directed at finding an analytical approach to determining the free energies solids as well as the barriers that separate various solid state structures from each other.
