I am trying to calculate the Franck-Condon factors for various tautomer. But, every time i get this type of error.

"ERROR: One imaginary frequency in final state.

You can use the option "ClearImFreq" to remove it automatically.

Error termination via Lnk1e in /usr/local/g16/l718.exe"

Any one tell me how i resolve this problem.

Thanks