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Where is "NWChem " located and how do I access it?

Please note: The FAQ pages at the HPCVL website are continuously being revised. Some pages might pertain to an older configuration of the system. Please let us know if you encounter problems or inaccuracies, and we will correct the entries.

The NWChem program is located in the directory /opt/nwchem/bin. To access it, you have to either include this directory in your path:

export PATH='/opt/nwchem/bin:'$PATH (for ksh) 
setenv PATH '/opt/nwchem/bin:'$PATH (for csh)

or (preferably) use the usepackage command

use nwchem

which will set you up automatically. You also need to have a NWChem setup file in your home directory. The best way to do this is to create another symbolic link

ln -s /opt/nwchem/data/default.nwchemrc $HOME/.nwchemrc

Note that the .nwchemrc file is "invisible" and may be checked out with the 'ls -la'command. A final thing that has to be done before you can run NWChem is to make sure the environment variable LD_LIBRARY_PATH includes the 64-bit high-performance libraries. You can check the variable by typing

echo $LD_LIBRARY_PATH

and if the directory /opt/SUNWhpc/lib/sparcv9 is not in there, include it by typing

export LD_LIBRARY_PATH='/opt/SUNWhpc/lib/sparcv9':$LD_LIBRARY_PATH (ksh) 
setenv LD_LIBRARY_PATH '/opt/SUNWhpc/lib/sparcv9':$LD_LIBRARY_PATH (csh)

The above setting will be applied automatically when you type use nwchem. Of course, these commands may be included in your setup files, so you don't have to type them each time you run NWChem. It might also be necessary to reset the LD_LIBRARY_PATH variable after using NWChem, particularly if you want to run MPI applications that use 32-bit addressing.