Talk:Mod3:610phy
Introduction Good introduction but some technical details such as energy derivatives and force constants could have been put in a ‘Computational methods’ section rather than in the introduction.
Cope rearrangement Most conformers identified. Good summary table and good discussion about their relative stability: One would expect, from the steric consideration, the ANTI conformer to be lower in energy than GAUCHE conformer. Labeling the atoms and maybe pictures of orbitals could help the understanding. Too many figures: Choose only the most important ones, the ones that you need to illustrate/ explain important points. Ask yourself: does the figure add some information to the text? eg Figure 4: which vibrational mode of the reactant is it? what do you want to illustrate? It would be more interesting to see an animation corresponding the imaginary frequency of the TS (with technique 1). Be careful: an IRC is not an optimisation. The path should follow the steepest descent path and if the number of steps is enough, it will end up in a minimum. But you can not say that in the optimisation calculation “the RMS gradient has decreased significantly to 0.00000171 signifying that a more successful optimisation has been performed than the previous IRC calculation”.
Diels Alder Plot orbitals of butadiene along the plane so it is easier to see the symmetry “There is a single imaginary frequency which is indicative of the transition state so the optimisation has been successful towards the transition state instead of the ground state.” The TS is also on the ground state. The [4+2] cyclization is thermally allowed according to Woodward-Hoffmann rules and so can proceed via a ground state mechanism. Maybe some correlation diagrams could have helped you pick out more secondary overlap effects, further work might have involved NBO analysis or a discussion of literature (not everyone is convinced these effects exist).
Overall In general a good report, you could have given more detail on the overall goal of the exercise and justify the methods used.