How can I overcome negative frequencies that occur during Gaussian calculations?. I elongated my atomic positions along the normal coordinates of my imaginary frequency. You see "quer-rc.out" file.
the negative frequency in your case correspond to rotation of phenyl ring. if you pay attention to the dihedral angle 12-10-14-15. in your optimized structure it is 0.0 degrees. Change it to +10 or -10 and then reoptimize it
hopefully it will be optimized without any negative frequency
1. You should check the vector of negative frequency then change the structure with respect to vector direction. Using of this structure, you need to recalculate.
2. If there are a lot of negative frequency, you need to add opt=calcall option then, it would be automatically remove negative frequency but it takes a lot of computing times
Check the Displacement vectors corresponding to that particular negative frequency then modify the structure with the Manual Displacement option and re-run the job again. All The best.