# The GAUSSIAN program system¶

Information regarding the quantum chemistry program system Gaussian

## General Information¶

### Description¶

Gaussian is a computational chemistry software program system initially released in 1970. Gaussian has a rather low user threshold and a tidy user setup, which, together with a broad range of possibilities and a graphical user interface (gaussview), might explain its popularity in academic institutions.

### Online info from vendor¶

The license of GAUSSIAN is commercial/proprietary.

The license of Gaussian constitutes of 4 site licenses for the 4 current host institutions of NOTUR installations; NTNU, UiB, UiO, UiT. In principle, only person from one of these institutions have access to the Gaussian Software system installed on Stallo.

• To get access to the code, you need to be in the gaussian group of users.
• To be in the gaussian group of users, you need either to be a member of the abovementioned institutions or provide proof of holding a license on your own.

### Citation¶

When publishing results obtained with the referred software referred, please do check the developers web page in order to find the correct citation(s).

### Usage¶

Since Gaussian is a rather large and versatile program system with a range of different binaries, we would in general advice users to check whether their jobs are parallelized or not before submitting jobs. It would in general, unless every step is entirely well parallelized, always be more efficient to split a complex many-step job into smaller parallel and serial parts/jobs so that also the overall utilization of hardware is improved. I you are in doubt whether or not your job will scale outside one node (=shared memory), go to the Gaussian application home folder and check if there is an *.exel version of the executable(s) you will be using. If yes, your job will generally work ok in parallel up to approx 300 cores (this is for the more advanced users).

We generally wants users to run as many nodes as possible to limit the walltime length of running jobs.

Use

$module avail Gaussian  to see which versions of Gaussian are available. Use $ module load Gaussian/<version> # i.e 09.d01