Gaussian 03 Online Manual
Last update: 29 September 2006

Utility Programs

This page discusses various utility programs included with Gaussian 03. The utilities are discussed in alphabetical order within this chapter.

Most utilities are available for both UNIX and Windows versions of Gaussian. However, be sure to consult the release notes accompanying the program for information pertaining to specific operating systems.

The following lists the available utilities and their functions (starred items are included on the Gaussian 03W Utilities menu):

c8603Converts checkpoint files from previous program versions to Gaussian 03 format.
chkchk*Displays the route and title sections from a checkpoint file.
cubegen*Standalone cube generation utility.
cubman*Manipulates Gaussian-produced cubes of electron density and electrostatic potential (allowing them to be added, subtracted, and so on).
formchk*Converts a binary checkpoint file into an ASCII form suitable for use with visualization programs and for moving checkpoint files between different types of computer systems.
freqchk*Prints frequency and thermochemistry data from a checkpoint file. Alternate isotopes, temperature, pressure and scale factor can be specified for the thermochemistry analysis.
freqmemDetermines memory requirements for frequency calculations.
gauoptPerforms optimizations of variables other than molecular coordinates.
ghelpOn-line help for Gaussian.
mmStandalone molecular mechanics program.
newzmat*Conversion between a variety of molecular geometry specification formats.
testrt*Route section syntax checker and non-standard route generation.
unfchk* Convert a formatted checkpoint file back to its binary form (e.g., after moving it from a different type of computer system).

GAUSS_MEMDEF Environment Variable

The GAUSS_MEMDEF environment variable may be used to increase the memory available to utilities which do not offer such an option themselves. Its value should be set to the desired amount of memory in words.