I am trying to do a QST2 calculation on two geometry optimized structures that I obtained by doing DFT calcs. The QST2 calc runs fine and finds 1 imaginary frequency resulting in a transition state that appears reasonable. However, when I pick points to the "left" and "right" of the transition state structure and optimize them back down, I find that the 1 optimized strucutre matches exactly to the input strucuture I originally put in, even in total energy. The structure to the "left" of the transition state optimizes back down but results in a structure that is similar to the original input structure but is off by almost 6kcal/mol in energy to my original input structure. Are there any alternatives to the QST2 calc that can be done in order to find transition states between 2 optimized geometries? Are there any tricks I can do in order to get the geometry to the "left" of the transition state to optimize back down to my original input structure (energy wise)? BTW I am currently using gaussian to do the calcs. -Thanks, GNW.