Talk:Mod:maw210

Introduction Short general introduction. Be careful: Gaussview is a software that allows you to visualize the molecules, the molecular orbitals for example and to interact with Gaussian – Gaussian actually does the calculation not Gaussview.

Cope rearrangement All conformers were successfully identified with a short comment about their relative energy. Good interpretation of the frequency calculation. Chair and Boat structures successfully identified with the different methods proposed. Be careful: the IRC method does not allow you to determine a Transition State structure but to identify which minima this TS connect. What did you conclude from this calculation? Short discussion about the preferred mechanism.

Diels-Alder “The dotted lines indicate that the electrons are delocalised and that the σ bonds have not yet completely formed, a characteristic trait of a transition state.” The dotted lines indicate an internuclear distance that is longer than the programmer has decided is a standard C-C single bond, however, it does not intrinsically mean that you have located a TS. Only a frequency analysis can determine this. “Since the two reactants do not move toward or away from each other in this positive vibrational mode, it does not correspond to the transition state.” It corresponds to a degree of freedom present at the TS but as the curvature of the PES in this direction is positive (as derived from the real frequency of the corresponding mode) it shows that symmetry breaking motion is uphill in energy and so symmetry is conserved through the TS.