Characterization of Enolate Rotamers PES scans, with Θ as the reaction coordinate, were conducted to identify the energetically stable enolate rotamers and are shown in Figure . The trends in Figure remain the same for each warhead: there are three energetic minima at Θ = 50 • , 310 • , and 180 • (from most to least stable, as determined by the magnitudes of ∆E values); these dihedral angles correspond to synclinal, antiperiplanar, and synclinal conformations, respectively. Furthermore, as shown in Figure (a), the PES scans calculated with CCSD(T)@MP2 and ωB97X-D3(BJ) closely match each other, with a mean absolute error of only 1.15 kcal mol -1 between the ∆E values calculated with ωB97X-D3(BJ) and CCSD(T)@MP2. Furthermore, the CCSD(T) calculations were found to have a mean average T 1 diagnostic value, which is the Euclidean norm of the singles amplitudes vector of the CCSD(T) wavefunction normalized by the square root of the number of correlated electrons, of 0.0146 and a standard deviation of 1.34 × 10 -4 . The dependence of T 1 on Θ can be seen in Figure (a). As the T 1 values are less than 0.02, the CCSD(T) results are reliable, and the energetics calculated with ωB97X-D3(BJ) can thus be deemed to be accurate.