The assumption that the reaction coordinate in going from gauche to anti n-butane is a simple torsion is an oversimplification, because other geometrical changes no doubt also occur during rotation around the carbon–carbon bond; for example, changes in bond lengths and angles. Examine the energy profile for n-butane (“n-butane” on the pre-calculated Spartan file) and plot the change in distance of the central C―C bond and C―C―C bond angle as a function of the torsion angle. Are the bond length and bond angle nearly identical or significantly different (>0.02 Å and >2°) for the two equilibrium forms of n-butane? Are the two parameters nearly identical or significantly different between the anti form and either or both of the transition states? Explain your results.