The default maximum number of SCF iterations is 2000. When this limit presents difficulty, ITRY=nn can be used to re-define it. For example, if ITRY=4000 is used, the maximum number of iterations will be set to 4000. ITRY should normally not be changed until all other means of obtaining a SCF have been exhausted, e.g. PULAY, CAMP-KING, etc.

If ITRY is set to 0, 1, or 2, then that number of iterations will be run then the SCF calculation will be stopped, and the normal output generated.  This option is useful when the SCF needs to be started, but the results of the SCF are not needed.