Scientific Application – NWChem

Overview

NWChem is a computational chemistry package that is 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 (EMSL) at the Pacific Northwest National Laboratory (PNNL).

NWChem provides many methods to compute the properties of molecular and periodic systems 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.

 

Research Computing Server(s): Kure, Killdevil
Default Version(s): 6.3
Installed Version(s): 6.0, 6.1.1, 6.3, 6.5

Setting up your Environment and Invoking

Before running NWChem, a NWChem input file is required. The input file should contain instructions on what kind of computation to perform, comments and the molecular description. The following support documents assume that you are using the NWChem input file input.nw. You can use any filename you want for your NWChem jobs.

Depending on your local computer setup, choose either of the following ways to access NWChem.

module add nwchem
module initadd nwchem

Notes

  • Other NWChem versions are also available for use. To use version 6.1.1 for example, please remove any other version of NWChem with the command:
ipm  r  nwchem

Version 6.1.1 can then be added with the command:

ipm  add  nwchem/6.1.1

NWChem version 6.1.1 can then be accessed in the same manner as used for the default version.

  • Since memory and scratch disk space are limited, we need to put the following two lines after the title line in your NWChem input file:

memory 1024 mb #limit to 1.0 GB for each processor

scratch_dir /netscr/$USER #temporary files not backed up

  • To view NWChem output graphically, you can use its sister package, ECCE, which is also available on Research Computing servers.

Links

Additional Help

Research Computing home pageĀ