The description of the keywords is grouped as follows according to their functionality: geometry input, methodology selection, atom specific inputs (basis sets, auxiliary functions etc.), electronic state control, self-consistent field (SCF) control, optimization and transition state search, Born-Oppenheimer molecular dynamics, molecular properties, electronic structure analysis, visualization/topological analysis, performance/accuracy settings, and miscellaneous. Keyword options which are mutually exclusive, i.e. are incompatible with one another, are listed on one line separated by / signs. If none of the options is specified in the input, the underlined one is used by default. If more than one of these options is given, the last one listed will override the preceding ones. Non-exclusive options are separated from exclusive ones by an extra blank line in the description block. The boldface printed part (first five letters) of the keywords and options are mandatory for the correct input interpretation by deMon2k. Therefore, OPTIMIZATION, OPTIMIZE, and OPTIM are all allowed input forms for the keyword OPTIMIZATION.