I perform some DFT calculations for transitional metal complexes which presumably have quite a flat hypersurface near the minimum. Therefore I'm struggling with getting rid of one (or sometimes two) imaginary frequencies. To get rid of this I sometimes use a brute force approach, i.e. opt=calcall option which computes force constants on each optimization step. With force constants already calculated, I would expect it to be possible to get a standard frequency analysis for each optimization step with little to no extra computational costs.

However, the standard frequencies module appears in the log file only for the final step which is in line with the Gaussian manual ("....Note that vibrational frequency analysis is automatically done at the converged structure and the results of the calculation are archived as a frequency job....").

With this being said, my question is if there is a way to get a standard frequency analysis for each optimization step (probably by using some IOps or another, not the most obvious workaround).

Thank you in advance!