Materials with a particular crystalline arrangement of atoms, known as perovskite, have played important roles in applications ranging from electronic and magnetic devices to micro-machined actuators and sensors. Some of the most interesting phenomena arise at interfaces between these and other materials, where the atomic and structural aspects combine to form new materials in their own right. The main goal of this research is the discovery of a new class of interface materials based on antiperovskites. These antiperovskites exchange the atomic positions of the more common perovskites, creating unique, wide-ranging properties different from the parent materials. Interfaces between these two 'anti'-structures create unexplored fundamental opportunities for materials design. This research will discover the fundamental principles controlling these new materials systems, develop atomic-scale design principles, and create and explore these interfaces for potential applications in electronic, magnetic, and quantum-controlled devices.