The nitride semiconductors, including gallium nitride (GaN), aluminum nitride (AlN), and indium nitride (InN) are the enabling materials for solid-state lighting based on light-emitting diodes. These materials are also used in power electronics, particularly for achieving power conversion (between alternating and direct current) with much higher efficiencies. In both areas, fabrication of high-quality nitride alloys with larger energy band gaps is desirable. In optoelectronics this will enable ultraviolet light emitters; in power electronics, higher voltage transistors. Computational theory, in tight collaboration with materials growth and characterization, will be used to accelerate these developments by exploring suitable alloy compositions and novel layer structures based on an atomistic, quantum-mechanical description of the materials. The results will have a strong impact on technologies ranging from optical data storage to water purification. Graduate and undergraduate students will benefit from the tight collaboration between theory and experiment. Outreach will take advantage of the Allosphere facility at the California Nanosystems Institute.