Four different model systems, designated I-IV and con- and consist primarily of some movement of a 4methylphenol ring, which is a truncated model of tyrosine and which turns slightly about the fixed anchor atom in our optimizations. Energetics are reported here at the B3LYP+D3/ 6-311+G(2df,2p)//B3LYP/6-31G(d,p) level, where the basis set used for the single-point energy calculations afford error statistics comparable to much larger basis sets, in benchmark tests. In Ref. 50, energetics were reported at the B3LYP/6-311+G(2d,2p)// B3LYP/6-31G(d,p) level but we consider that the use of dispersion-corrected B3LYP is important for conformational energies, thermochemistry, and barrier heights. In Ref. 50, vibrational frequency calculations were omitted for model IV but they are reported here.