Table of Contents

	Capabilities of Gaussian
	Running Gaussian at the AHPCC
	Sample Gaussian Input Files
	Where to find more information about Gaussian
	Legal Details

Capabilities of Gaussian

Quick Summary of supported methods.

• SCF energies, gradients, and frequencies (RHF, ROHF, UHF, GVB, CASSCF).
• MP2-MP5 energies, gradients, and frequencies (RHF, UHF).
• CID, CISD energies, gradients, and frequencies (RHF, ROHF, UHF).
• G1, G2, G2MP2 energies (RHF, UHF).
• AM1, CNDO, INDO, PM3, MINDO/3, MNDO energies, gradients, and frequencies (RHF, ROHF, UHF).
• LSDA, BLYP, Becke88, etc. energies, gradients, and frequencies (RHF, ROHF, UHF).
• Many additional energy and property methods.

Running Gaussian at the AHPCC

To run Gaussian follow these steps:

	Follow the instructions in the getting started section.
	Prepare an input file and append .com to the name, i.e. h2o.com.
	Run the calculation with the command "gaussian h2o" substituting the prefix of your input file for h2o.
	You may be asked platform specific information, such as the number of nodes you wish to use. Answer these prompts as you wish.
	Gaussian will create an output file with the same prefix as your input file, i.e. h2o.log.

Sample Gaussian Input Files

A sample input file is shown below. This will run a RHF/3-21G single point calculation on N₂. If the input file had the name n2.com you would would run the calculation with the command "gaussian n2". The output file will have the name n2.log.

-----Cut Here-----
% Mem=2000000
# RHF/3-21G

N2

0 1
N1
N2 N1 r1

r1 1.1


-----Cut Here-----

Take a look at the output file produced by the above input file.

Gaussian Command Line Options

Almost all the functionality of Gaussian is controlled by command line options. Here are some useful commands to remember:

# RHF/3-21G	Perform a single point calculation.
# RHF/3-21G Opt	Perform a geometry optimization.
# RHF/3-21G Freq	Perform a frequency calculation.
# RHF/3-21G GFInput Pop=Full	Print information about the basis set and molecular wavefunction.

See the documentation for details on these and other commands.

Gaussian Z-Matrix Format

The Gaussian z-matrix format is a very powerful way of specifying molecular geometries. It allows you to easily specify molecular symmetry and perform constrained geometry optimization. However, it does take a little practice.

Here are many sample gaussian input files in z-matrix format.

Where to find more information about Gaussian

Documentation can be found in the form of a series of text files in the ~chem/gaussian/manuals directory. The file 3_input.txt describes the input format and most command line options. This information is also available in html format here.

A large number of sample input and output files can be found in the ~chem/gaussian/tests directory or from this page.

Also, check out the Gaussian home page.

Legal Details

Gaussian is a commercial product. It is available from Gaussian, Inc. at the following address.

or call (412)-279-6700

or email info@gaussian.com

Literature Citation:

Gaussian 94, Revision D.3,
M. J. Frisch, G. W. Trucks, H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb, J. R. Cheeseman, T. Keith, G. A. Petersson, J. A. Montgomery, K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B. Stefanov, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, D. J. Defrees, J. Baker, J. P. Stewart, M. Head-Gordon, C. Gonzalez, and J. A. Pople,
Gaussian, Inc., Pittsburgh PA, 1995.

Copyright:

Copyright (c) 1988,1990,1992,1993,1995 Gaussian, Inc. All Rights Reserved.

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