This project focuses on the investigation of the properties of quantum gases in optical lattices. Questions to be addressed include the precise point at which the phase transition occurs, as measured by a vanishing superfluid content of the gas, the dependence of this phase transition point on parameters such as the occupancy of the lattice sites, and the proportion of defects which can feasibly be achieved in the insulating state of the gas. The production of correlated molecular gases by Raman photoassociation of atomic gases will be studied. Further, melting of the Mott-insulating phase will be studied, and could lead to the production and study of a molecular condensate under favorable conditions. The broader impact involves the education of the students and applications to other fields including quantum information.