NWChem, cutting-edge software developed by researchers at the DOE Environmental Molecular Sciences Laboratory, is made to order to tackle the large, challenging scientific problems in energy, environment, and health.
This innovative tool both answers fundamental questions and leads to practical solutions. It yields a full understanding of chemical processes, thus allowing researchers to predict the behavior of chemical systems. Understanding at this level is critical to efficiently design and synthesize tailored chemical systems, such as those with applications to catalysis and alternative energy production.
NWChem is a large and complex code that consists of over two million lines of Fortran and C code, and provides many methods to compute the properties of molecular and periodic systems using standard quantum mechanical descriptions of the electronic wave function or density. Its classical molecular dynamics capabilities provide for the simulation of biological macromolecules and solutions. The object-oriented programming model enables the various approaches to be combined to perform, for example, mixed quantum mechanics and molecular-mechanics simulations.
Enhancing Scientific Discovery
Researchers around the world download and use NWChem to gain a fundamental understanding of large, complex chemical systems of national interest and to create predictive models of chemical systems with an unprecedented level of mechanical and chemical accuracy. NWChem has been used to investigate many chemical systems that have important applications to a broad range of energy- and environment-related research areas, including catalysis, nanoscience, solar energy, hydrogen economy, atmospheric science, environmental remediation, and biology.
NWChem is designed to scale to many computer systems, and it demonstrates its full capacity when coupled to world-leading massively parallel processing (MPP) supercomputing resources, such as EMSL’s Chinook. Using MPP techniques, one large, complex, real-world calculation is solved in smaller pieces, and those pieces are compiled at the end of the calculation to yield an answer.
NWChem is part of a suite of software called MS3, which comprises NWChem, Ecce, and ParSoft. The last is a library of tools that includes the Global Array Toolkit, which provides an efficient and portable shared-memory programming interface for distributed-memory computers (sidebar “GA/ARMCI” p14). Ecce (Extensible Computational Chemistry Environment) provides a graphical user interface, scientific visualization tools, and an underlying data management framework. The MS3 suite won an R&D 100 award in 1999 and a Federal Laboratory Consortium Award in 2000. NWChem impacts scientific research and discovery have been numerous.
Though NWChem is a computational tool, its impact extends to experimental sciences. For example, NWChem is used to interpret complex experimental data, such as those generated by high-resolution spectroscopy techniques. Those data are then used to further refine computational models. Also, when integrated with experimental resources, NWChem adds synergy to research, lowers project costs, and yields quicker results. For example, NWChem can be used to model materials for specific applications, allowing scientists to identify promising candidates to then build and test at the bench.