PNNL

Abstract

Computational atomistic modeling has emerged as a powerful approach for fundamental studies in chemistry, materials science, geosciences, and biology. It has the ability to provide detailed insights into complex phenomena and over the years has grown into a powerful tool not only to validate experiment, but also to predict new phenomena. In order to harness computational modeling to the fullest, superior computational tools are required that not only offer a broad spectrum of capabilities, but are also capable of taking advantage of modern massively parallel computer architectures efficiently to solve real world problems. The NWChem program suite is an example along these lines. It offers a range of capabilities to perform first-principles electronic structure calculations on molecular and periodic systems, classical molecular dynamics simulations and hybrid QM/MM simulations that permits one to combine quantum and classical methods within a calculation. The code is designed to run on high-performance parallel supercomputers as well as conventional workstation clusters with the goal to provide scalable solutions for large scale atomistic simulations. It has been ported to almost all high-performance computing platforms, workstations, PCs running LINUX, as well as clusters of desktop platforms or workgroup servers. The package is scalable, both in its ability to treat large problems efficiently, and in its utilization of available parallel computing resources. The parallel framework for NWChem is provided by the Global Array (GA) toolkit developed at PNNL. NWChem is developed and maintained by the Environmental Molecular Sciences Laboratory (EMSL) located at the Pacific Northwest National Laboratory (PNNL) in Washington State. The latest release (version 6.0) of the code is distributed under the terms of the Educational Community License (ECL) version 2.0.