In the 1980s, it became clear that decommissioning and rehabilitation of the nuclear weapons complex operated by contractors of the U.S. Department of Energy (DOE) was a monumental challenge. The weapons sites contained tens of millions of gallons of high level radioactive wastes and hundreds of cubic kilometers of contaminated soils as well as thousands of contaminated facilities. Towards the end of the 1980s, Robert S. Marianelli, Director of the Chemical Sciences Division in DOE’s Office of Science (DOE-SC) and William R. Wiley, Director of the Pacific Northwest National Laboratory began laying plans for a major new laboratory that would focus on gaining the fundamental understanding needed to tackle these problems. Their work eventually led to the construction of the Environmental Molecular Sciences Laboratory (EMSL), a national user facility dedicated to molecular research related to environmental science and waste processing.

The size of molecular systems involved in environmental science (e.g., aqueous solutions) and high level wastes (e,g., trans-uranic compounds and metal ion chelating agents) was considerably beyond those that could be studied with the molecular modeling software and computing resources available at the time. A workshop was convened in February 1990 to discuss the approach to be taken. The report from the workshop recommended that the DOE-SC establish a major new computing facility in the EMSL and, simultaneously, make a major investment in the development of new quantum chemistry software designed explicitly for massively parallel computing systems. Thus began the development of the Northwest Chemistry package (NWChem).^{1 2 3 4} Although the official start of the project would be delayed for another couple of years, work began soon thereafter exploring technologies that could be used for a new, scalable quantum chemistry application that included the major atomic and molecular electronic structure methods (e.g., Hartree-Fock, perturbation theory, coupled cluster theory, etc.) as well as molecular dynamics simulations with empirical, semiempirical or ab initio potentials.

One of the authors (Dunning) instigated the NWChem project, while the other authors were the chief architect (Harrison) and project manager (Nichols).