Table 1. Relative Energies at Canonical UCCSD(T)/6-311G(d,p)//UDFT/6-311G(d,p) (Normal Print) and CASPT2/ANO-RCC-VDZP//UDFT/6-311G(d,p) (Italics) Level with UB3LYP, UM06-2X, and UCAM-B3LYP Geometriesa.
| geometries | B3LYP | CAM-B3LYP | M06-2X |
|---|---|---|---|
| 3C8H8 | 0.0, 0.0 | 0.8, 0.4 | 0.4, 0.2 |
| 3C12H12 | 0.0, 0.0 | (4.4)b, 1.5 | (4.4)b, 0.0 |
| 3C16H16 | 0.0, 0.0c | (7.6)b, 2.4c | 1.4, 0.9c |
a
UHF reference wavefunction in UCCSD(T) calculation. Relative energies in kcal/mol.
b
Values in parentheses are results for which the spin contamination in the reference exceeds 20%, as seen in Table S5.
c
CASPT2 calculations for 3C16H16 run with the 6-31G(d) basis set.