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NWChem

Description

NWChem is a computational chemistry package 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.

How to access NWChem

NERSC uses modules to manage access to software. To use the default version of NWChem, type:

% module load nwchem

To see where the nwchem executables reside (the bin directory) and what environment variables it defines:

% module show nwchem

For example, on Edison:

% module avail nwchem
----------------------------------- /usr/common/usg/Modules/modulefiles -------------------------------
nwchem/6.1.1 nwchem/6.3 nwchem/6.3.r25564 nwchem/6.5(default)

To see what environment variables the default nwchem module, nwchem/6.5, defines, do 

 

% module show nwchem
-------------------------------------------------------------------
/usr/common/usg/Modules/modulefiles/nwchem/6.5:
module-whatis NWChem is a parallel computational chemistry package
setenv NWCHEM_BASIS_LIBRARY /usr/common/usg/nwchem/6.5/data/libraries/
prepend-path PATH /usr/common/usg/nwchem/6.5/bin
-------------------------------------------------------------------

When you first start to use NWChem, you should copy a default ".nwchemrc" file to your home directory. This file is used to set certain default options for the program:

% cp ${NWCHEM_DIR}/default.nwchemrc ~/.nwchemrc

How to Use NWChem on Edison and Cori

There are two ways of running NWChem, submitting a batch job, or running interactively in an interactive batch session. A sample batch script to run NWChem on Edison and Cori is shown below:

#!/bin/bash -l
#SBATCH -J test_nwchem
#SBATCH -p debug
#SBATCH -N 2
#SBATCH -t 30:00
#SBATCH -o test_nwchem.o%j

module load nwchem

#for Edison which has 24 cores per node
srun -n 48 nwchem test1.nw >& test1.out

##for Cori which has 32 cores per node:
#srun -n 64 nwchem test1.nw >& test1.out

Then submit the job script using the sbatch command, e.g., assume the job script name is test_nwchem.slurm,

% sbatch test_nwchem.slurm

2) To request an interactive batch session, issue a command (e.g., requesting 2 nodes):

% salloc -N 2 -p debug -t 30:00

when a new batch session prompts, issue the following commands:

%  module load nwchem 
% srun -n 48 nwchem test1.nw # on Edison

or

%  srun -n 64 nwchem test1.nw     # on Cori

Documentation

NWChem was developed by the High-Performance Computational Chemistry group in the Environmental Molecular Sciences Laboratory (EMSL) at the Pacific Northwest National Laboratory (PNNL).

NWChem User Manual

Availability

PackagePlatformCategoryVersionModuleInstall DateDate Made Default
NWChem babbage applications/ chemistry 6.5 nwchem/6.5 2015-06-19
NWChem edison applications/ chemistry 6.1.1 nwchem/6.1.1 2013-03-22 2013-04-17
NWChem edison applications/ chemistry 6.3 nwchem/6.3 2013-08-31 2013-08-31
NWChem edison applications/ chemistry 6.3.r25564 nwchem/6.3.r25564 2014-07-03
NWChem edison applications/ chemistry 6.5 nwchem/6.5 2014-11-09
NWChem edison applications/ chemistry 6.6 nwchem/6.6 2016-05-02