Q-Chem 4.3 User’s Manual

3.21 Natural Bond Orbital Package ($nbo)

The default action in Q-Chem is not to run the NBO package. To turn the NBO package on, set the $rem variable NBO to ON. To access further features of NBO, place standard NBO package parameters into a keyword section in the input file headed with the $nbo keyword. Terminate the section with the termination string $end.