ASCR Leadership Computing Challenge (ALCC)

The call for the ALCC 2022-2023 allocation year is expected to open in Fall 2021. Please check back for more information.

ALCC Mission

The mission of the ASCR Leadership Computing Challenge (ALCC) is to provide an allocation program for projects of interest to the Department of Energy (DOE) with an emphasis on high-risk, high-payoff simulations in areas directly related to the DOE mission, that respond to National emergencies, and for broadening the community of researchers capable of using leadership computing resources.

Current Awards

ALCC grants one year awards which are active from July 1 to June 30 of the following calendar year. For a listing of 2021-22 awarded projects see Current Awards. For awards from previous years see Past Awards

Overview of ALCC

Open to scientists from the research community in industry, academia, and national laboratories, the ALCC program allocates from 10% to 30% of the computational resources at ASCR’s three supercomputing facilities. ASCR supercomputing facilities include NERSC at Lawrence Berkeley National Laboratory and the Leadership Computing Facilities at Argonne and Oak Ridge National Laboratories. These resources represent some of the world’s fastest and most powerful supercomputers.

ALCC is one of several allocation programs for ASCR supercomputing facilities (see ASCR Allocation Policy ) and supports ASCR’s efforts to further DOE mission science, respond to National emergencies, and to broaden community access to leadership computing facilities. To fulfill its goal of broadening community access, ALCC supports a range of project allocation sizes and allocates time across all three ASCR supercomputing facilities. However, very large projects are encouraged to apply to the INCITE allocation program. Projects that request more than 25% of the available resources at any facility will be considered nonresponsive and may be declined without review.

Scientific discovery advanced by ALCC allocations range across the DOE mission space such as energy efficient engineering, computer science, materials and chemical sciences, geosciences and energy-related biosciences,  biological and environmental sciences, computational fluid dynamics, high energy and nuclear physics, cosmology, the design and control of scientific user facilities and experiments at these facilities, nuclear energy, fossil energy and renewable energy. (See ALCC Past Awards and ALCC FAQ.) 

ALCC Resources

ALCC allocates high performance computing time on the primary HPC machines at each ASCR facility. For the 2022-23  ALCC, these resources include Summit at Oak Ridge National Laboratory, Theta at Argonne National Laboratory, and the Cori/KNL partition at Lawrence Berkeley National Laboratory. For a description of the computing resources at ASCR facilities, please see

See side bar for more ALCC information links.