Job Scripts

A job script, or PBS batch script, is a text file containing job setup information for the batch system followed by commands to be executed. It can be created using any text editor and may be given any name. Some people like to name their scripts something like myscript.job or myscript.pbs, but myscript works just as well.

A job script is simply a shell script. It consists of PBS directives, comments, and executable statements. The # character indicates a comment, although lines beginning with #PBS are interpreted as PBS directives. Blank lines can be included for readability.


HDF5 is a general purpose library and file format for storing scientific data. HDF5 can store two primary objects: datasets and groups. A dataset is essentially a multidimensional array of data elements, and a group is a structure for organizing objects in an HDF5 file. Using these two basic objects, one can create and store almost any kind of scientific data structure, such as images, arrays of vectors, and structured and unstructured grids.


Gaussian is the most popular general purpose electronic structure program. Recent versions can perform density functional theory, Hartree-Fock, Möller-Plesset, coupled-cluster, and configuration interaction calculations among others. Geometry optimizations, vibrational frequencies, magnetic properties, and solution modeling are available. It performs well as black-box software on closed-shell ground state systems. 

Batch System Concepts

The only access to significant resources on the HPC machines is through the batch process.

Why use a batch system?

Access to the OSC clusters is through a system of login nodes. These nodes are reserved solely for the purpose of managing your files and submitting jobs to the batch system. Acceptable activities include editing/creating files, uploading and downloading files of moderate size, and managing your batch jobs. You may also compile and link small-to-moderate size programs on the login nodes.


FFTW is a C subroutine library for computing the Discrete Fourier Transform (DFT) in one or more dimensions, of arbitrary input size, and of both real and complex data. It is portable and performs well on a wide variety of platforms.

Getting Connected

There are two ways to connect to our systems. The traditional way will require you to install some software locally on your machine, including an SSH client, SFTP client, and optionally an X Windows server. The alternative is to use our zero-client web portal, OnDemand.


The Assisted Model Building with Energy Refinement (AMBER) package contains many molecular simulation programs targeted at biomolecular systems. A wide variety of modelling techniques are available. It generally scales well on modest numbers of processors, and the GPU enabled CUDA programs are very efficient.