How do I set up my environment for Gaussian ?

There are two ways to set up your environment to enable Gaussian.

• The easy way: The usepackage system has an entry for Gaussian 09 (and other ones for Gaussian '98 and '03). All you need to do is type use g09and the proper changes will be made. You can also put this command into your setup files, e.g. .bash_profile for bash.

• The hard way: You can also do things manually. Include the following lines in your setup files (.login for csh, .bash_profile for ksh or bash):

  For csh: 
  setenv g09root /opt/gaussian 
  source $g09root/g09/bsd/g09.login 
  setenv GAUSS_SCRDIR /scratch/hpcxxxx 

  For bash: 
  export g09root=/opt/gaussian . 
      $g09root/g09/bsd/g09.profile 
  export GAUSS_SCRDIR='/scratch/hpcxxxx'

Note that the setting of the environment variable GAUSS_SCRDIR is necessary to redirect the temporary files that Gaussian creates to the proper scratch space. This directory should be /scratch/hpcxxxx (replace the xxxx by your username's numbers). This is done automatically if you apply the use command.

Also note that if for some reason Gaussian does not terminate normally (e.g. a job gets cancelled by hand), it leaves behind large "scratch files" which you should delete by hand. To check if such files exist, type

ls -lt /scratch/hpcxxxx

where xxxx stands for the numbers in your username. Once you have determined that the scratch files are no longer needed, you can delete them by typing

rm /scratch/hpcxxxx/Gau-* 

where, again, xxxx needs to be replaced by the numbers in your username.

Cleaning up the scratch space is the user's responsibility and cannot be done by the system administrator. If scratch space does not get cleaned up regularly, it can cause jobs to terminate, and much work to be lost. Please do it.