formchk

formchk converts the data in a Gaussian checkpoint file into a formatted form which is suitable for input into a variety of visualization software.

formchk has the following syntax:

formchk [options] chkpt-file formatted-file

where chkpt-file is the name of the binary checkpoint file to be formatted, and formatted-file is the name for the resultant output file. For example, the following command will produce the formatted checkpoint file propell.fchk from the checkpoint file propell.chk:

$ formchk propell.chk propell.fchk

The conventional extension for formatted checkpoint files is .fchk on Unix systems and other computers supporting variable-length extensions, and .fck on systems which limit extension to three characters like Windows.

Note that formatted checkpoint files can be used as a data exchange format between computer platforms. Use formchk on the originating computer and unfchk on the target computer to create a binary checkpoint file. Always include the -3 option when moving files between different types of computers (see below).

OPTIONS

By default formchk produces a formatted checkpoint file that is backwardly compatible with all previous versions of Gaussian.

-3
Produce a version 3 formatted checkpoint file, including all features supported in Gaussian 09 (e.g., user-defined MM types, redundant coordinate definitions, values, forces, and the Hessian).

-2
Produce a version 2 formatted checkpoint file. This was the version used with Gaussian 03.

-c
Causes the molecular mechanics atom types to appear in the formatted checkpoint file as strings rather than integers.

 


Last update: 23 April 2013