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Re: How to repeat a vibrational analysis without repeating the SCF?

Alex Granovsky


The $HESS group is not mass-weighted.

You need to add $hess, $dipdr and optionally $alpdr groups
from the punch (.dat) file generated by the preceding Firefly's
run to your input and specify


as well as desired values of masses in the $MASS group while
leaving SCFTYP option intact as it is intended for completely different purpose.

Hope this helps.

Kind regards,
Alex Granovsky

On Mon Dec 25 '17 5:21pm, Bernhard Dick wrote
>I want to repeat a HESSIAN run but only change one atomic mass. Hence I do not need a new wavefunction calculation, it should be sufficient to read the $HESS group and the $DIPDR group with RDHESS=.T. in $FORCE, and the $MASS group. However, SCFTYP=NONE produces an error message. Is there a way to suppress repeating the SCF?

>Is the $HESS group already mass-weighted? It seems to me that this is the true cartesian second derivatives, i.e. it should be correct even if isotope substitution lowers the symmetry?

>best regards,


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