formchkconverts the data in a Gaussian checkpoint file into a formatted form which is suitable for input into a variety of visualization software.
formchkhas the following syntax:
formchk[options]chkpt-file formatted-file
wherechkpt-fileis the name of the binary checkpoint file to be formatted, andformatted-fileis the name for the resultant output file. For example, the following command will produce the formatted checkpoint filepropell.fchkfrom the checkpoint filepropell.chk:
$formchk propell.chk propell.fchk
The conventional extension for formatted checkpoint files is.fchkon Unix systems and other computers supporting variable-length extensions, and.fckon 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. Useformchkon the originating computer andunfchkon the target computer to create a binary checkpoint file. Always include the-3option when moving files between different types of computers (see below).
By defaultformchkproduces 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