NWChem - computational chemistry on parallel
computers


NWChem 3.1 Functionality and Capabilities

NWChem 3.3.1 Functionality and Capabilities

NWChem provides many methods to compute the properties of molecular and periodic systems by using standard quantum mechanical descriptions of the electronic wavefunction or density. In addition, NWChem has the capability to perform classical molecular dynamics and free energy simulations. These approaches may be combined to perform mixed quantum-mechanics and molecular-mechanics simulations.

NWChem is available on almost all high performance computing platforms, workstations, PCs running LINUX, as well as clusters of desktop platforms or workgroup servers. NWChem development has been devoted to providing maximum efficiency on massively parallel processors. It achieves this performance on the 512 node IBM SP system in the EMSL's MSCF and on the 512 node CRAY T3E-900 system in the National Energy Research Scientific Computing Center. It has not been optimized for high performance on single processor desktop systems.

1. Molecular electronic structure

The following quantum mechanical methods are available to calculate energies, and analytic first derivatives with respect to atomic coordinates. Second derivatives are computed by finite difference of the first derivatives.

The following methods are available to compute energies only. First and second derivatives are computed by finite difference of the energies.

For all methods, the following operations may be performed:

In addition, automatic interfaces are provided to:

2. Pseudopotential plane-wave electronic structure

The following modules are available to compute the energy, minimize the geometry and perform ab initio molecular dynamics using pseudopotential plane-wave DFT with local exchange-correlation potentials.

With

3. Periodic system electronic structure

A module (Gaussian Approach to Polymers, Surfaces and Solids (GAPSS)) is available to compute energies by periodic Gaussian based DFT with many local and non-local exchange-correlation potentials.

4. Molecular dynamics

The following classical molecular simulation functionality is available:

NWChem also has the capability to combine classical and quantum descriptions in order to perform:

The classical force field includes:

5. Parallel tools and libraries (ParSoft)