The ALCC allocation will be used for research and development (R&D) activities of the Exascale Computing Project (ECP), which include the development of exascale-capable Department of Energy (DOE) mission critical applications, implementations of computing motifs that are widely used, and optimization of many components of the exascale software stack. The ECP will develop scientific and large-data applications that exploit the emerging exascale-era computational architectures.

The majority of the applications codes that will receive time for exascale development are mature petascale codes that address major DOE programs and are already in use at the various ASCR leadership computing facilities. These representative codes cover science themes in accelerator physics, additive manufacturing, astrophysics, chemistry, climate, combustion, cosmology, materials, multiphase flows and computational fluid dynamics, fusion, nuclear physics, nuclear reactors, precision medicine and genomics, and subsurface modeling.

The software technology projects represent programming models and runtimes, tools, mathematical and scientific libraries and frameworks, data management and workflows, data analytics and visualization, system software, and resilience and integrity. The projects are critical components in the software stack for future exascale systems and form the infrastructure underpinning all ECP applications. The ALCC allocation will be used for testing newly developed features in these projects, for performance testing, and for testing the software at large scale.

The ECP R&D projects requiring computing resources through the ALCC program were selected with input from DOE stakeholders (e.g., program managers and senior staff) and are those that are important and relevant to programmatic mission needs.