NWChem is an ab initio

Ab initio quantum chemistry methods

Ab initio quantum chemistry methods are computational chemistry methods based on quantum chemistry. The term ab initiowas first used in quantum chemistry by Robert Parr and coworkers, including David Craig in a semiempirical study on the excited states of benzene.The background is described by Parr...

 computational chemistry

Computational chemistry

Computational chemistry is a branch of chemistry that uses principles of computer science to assist in solving chemical problems. It uses the results of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures and properties of molecules and solids...

 software package which also includes quantum chemical and molecular dynamics functionality.
It was designed to run on high-performance parallel supercomputers as well as conventional workstation clusters. It aims to be scalable both in its ability to treat large problems efficiently, and in its usage of available parallel computing resources. NWChem has been developed by the Molecular Sciences Software group of the Theory, Modeling & Simulation program of the Environmental Molecular Sciences Laboratory

Environmental Molecular Sciences Laboratory

Environmental Molecular Sciences Laboratory Environmental Molecular Sciences Laboratory Environmental Molecular Sciences Laboratory (EMSL, is a national scientific user facility at the Pacific Northwest National Laboratory, Richland, Washington. EMSL is a facility that provides integrated...

 (EMSL) at the Pacific Northwest National Laboratory

Pacific Northwest National Laboratory

Pacific Northwest National Laboratory is one of the United States Department of Energy National Laboratories, managed by the Department of Energy's Office of Science. The main campus of the laboratory is in Richland, Washington....

 (PNNL). Most of the implementation has been funded by the EMSL Construction Project.

Capabilities

• Molecular mechanics
  Molecular mechanics
  Molecular mechanics uses Newtonian mechanics to model molecular systems. The potential energy of all systems in molecular mechanics is calculated using force fields...
  
  
• Molecular dynamics
  Molecular dynamics
  Molecular dynamics is a computer simulation of physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a period of time, giving a view of the motion of the atoms...
  
  
• Hartree–Fock (self-consistent field method)
• Density functional theory
  Density functional theory
  Density functional theory is a quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by...
  
  
• Time-dependent density functional theory
  Time-dependent density functional theory
  Time-dependent density functional theory is a quantum mechanical theory used in physics and chemistry to investigate the properties and dynamics of many-body systems in the presence of time-dependent potentials, such as electric or magnetic fields...
  
  
• Post-Hartree–Fock methods, including MP2 in the resolution of identity approximation (RI-MP2), multiconfigurational self-consistent-field (MCSCF) theory, selected configuration interaction (CI), Møller–Plesset perturbation theory (MP2, MP3, MP4), configuration interaction
  Configuration interaction
  Configuration interaction is a post-Hartree–Fock linear variational method for solving the nonrelativistic Schrödinger equation within the Born–Oppenheimer approximation for a quantum chemical multi-electron system. Mathematically, configuration simply describes the linear combination...
  
   (CISD, CISDT, CISDTQ), and coupled cluster
  Coupled cluster
  Coupled cluster is a numerical technique used for describing many-body systems. Its most common use is as one of several quantum chemical post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry...
  
   theory (CCSD, CCSDT, CCSDTQ, EOMCCSD, EOMCCSDT, EOMCCSDTQ). The Tensor Contraction Engine, or TCE, provides most of the functionality for the correlated methods, and can be used to develop additional many-body methods using a Python interface. A full list of approximate coupled-cluster methods is available on the website.
• QM/MM
  QM/MM
  The hybrid QM/MM approach is a molecular simulation method that combines the strength of both QM and MM calculations, thus allowing for the study of chemical processes in solution and in proteins. The QM/MM approach was introduced in the 1976 paper of Warshel and Levitt .An important advantage...
  
  
• ONIOM
  ONIOM
  The ONIOM is a computational approach developed by Morokuma and co-workers...
  
  

External links

with the included and GUI shell for Windows

Graphic shells

• ECCE (official GUI for NWChem) - input generation, remote submission, analysis, extensive visualization
• Ascalaph Designer
  Ascalaph Designer
  Ascalaph Designer is a general purpose molecular modelling package for molecular design and simulations. It provides a graphical environment for the common programs of quantum and classical molecular modelling NWChem, Firefly, CP2K and MDynaMix...
  
   - model construction - results analysis.
• Jmol
  Jmol
  Jmol is an open-source Java viewer for chemical structures in 3D,that does not require 3D acceleration plugins.Jmol returns a 3D representation of a molecule that may be used as a teaching tool, or for research e.g...
  
  - cross-platform viewer.