The ghelp utility is a hierarchical help facility for Gaussian. Typing ghelp alone will display general information and a list of topics for which help is available. The form ghelp topics will display just the list of topics.
Information about Gaussian keywords and options is available using the format:
ghelp route keyword [option]
Information about Gaussian utilities may be accessed using either the utility name as the primary topic or via the topic utilities. Information about internal option m in overlay n (IOp(n/m)) may be obtained using the following command on Unix systems (note the quotation marks):
$ ghelp "ovn iop(m)"
Last updated on: 07 November 2016. [G16 Rev. C.01]