Units of vibrational eigenvectors

Hello,

I was wondering what exactly the eigenvectors printed in a standard frequency calculation are. I could not find the information in the manual. Also, some answers in the forum did not clear it up for me, as it was stated that they provide the transformation from mass-weighted Cartesians to normal modes, but also that they are mass-unweighted and transform normal modes to Cartesian.

I need to generate displaced geometries along the different normal modes. Thus, I require a dimensionless transformation, M, such that in Cartesian coordinates I can do: X = X0 + d·M. If the printed vectors correspond to the transformation normal modes to Cartesian, and are not mass-weighted nor frequency-weighted, they would already be appropriate. But if not, I need to do the proper conversions.

Thank you in advance for any help!

Looking at the code, it appears these are not mass weighted, i.e., it is the normal mode ==> Cartesian transformation matrix that is printed.

A check would be that the normal modes should fix the molecular center of mass.