Science and engineering research has evolved to increasingly rely on data-intensive and artificial intelligence (AI) driven methodologies. This, in turn, has led to more complex workflows that involve hardware and software resources at different scales and operating in different environments. These growing complexities necessitate a flexible and heterogeneous hardware and software infrastructure that transforms existing, disjointed workflows via a seamless and more productive computational environment that is easier and more intuitive to use. Nexus provides such a critical national resource to the science and engineering research community; it serves both as a standalone platform and as a gateway to effectively utilizing other national resources, significantly accelerating AI-driven scientific discovery. Nexus will advance American leadership in artificial intelligence and advantage U.S.-based research and industry enterprises in diverse areas of science and engineering, enabling breakthrough discoveries, increasing economic competitiveness, and advancing human health. Nexus is a next-generation, national-scale computational resource integrating cutting-edge heterogeneous hardware, AI-accelerated computing, and advanced software services to unify scientific and engineering research workflows. Led by the Georgia Institute of Technology in collaboration with the National Center for Supercomputing Applications (NCSA) at the University of Illinois Urbana-Champaign, Nexus prov