Table 5. CMA-0A and CMA-2A Residuals (ϵ, cm–1) for CCSD(T)/cc-pVTZ Harmonic Frequencies (ωref, cm–1) of Pyridine Obtained with Various Level B Methods.
| Mode | Description | ωref | ϵ[CMA-0A] |
ϵ[CMA-2A] |
|||||
|---|---|---|---|---|---|---|---|---|---|
| B = CCSD(T)/cc-pVDZ | B = MP2/cc-pVTZ | B = B3LYP/6-31G(2df,p) | B = CCSD/cc-pVTZ | B = MP4/cc-pVTZ | B = CCSD(T)/cc-pVDZa | B = MP2/cc-pVTZb | |||
| ω1(a1) | sym. CH str. | 3212.85 | –0.01 | –0.05 | –0.03 | 0.00 | 0.00 | –0.01 | –0.06 |
| ω2(a1) | asym. CH str. | 3187.57 | –0.01 | 0.01 | –0.08 | –0.01 | 0.00 | 0.03 | 0.06 |
| ω3(a1) | asym. CH str. | 3169.83 | 0.01 | 0.05 | 0.08 | 0.01 | 0.01 | –0.03 | 0.02 |
| ω4(a1) | ring str. def. | 1630.29 | –0.47 | –0.21 | –0.02 | –0.01 | –0.06 | –0.01 | –0.18 |
| ω5(a1) | sym. CH rock | 1510.12 | –0.48 | 0.10 | –0.05 | 0.01 | 0.04 | –0.15 | 0.10 |
| ω6(a1) | asym. CH rock | 1236.72 | 0.50 | 0.08 | 0.03 | 0.00 | 0.02 | –0.02 | 0.08 |
| ω7(a1) | sym. CH rock | 1087.86 | –0.37 | –0.07 | 0.00 | 0.00 | –0.06 | –0.89 | –0.07 |
| ω8(a1) | ring stellation | 1043.14 | –3.24 | 0.00 | –0.16 | 0.00 | –0.02 | 1.06 | 0.00 |
| ω9(a1) | ring breathing | 1001.24 | 4.61 | 0.16 | 0.30 | 0.01 | 0.10 | 0.14 | 0.17 |
| ω10(a1) | ring rectangle | 603.31 | 0.10 | 0.02 | 0.08 | 0.01 | 0.01 | 0.03 | 0.02 |
| ω11(a2) | asym. CH wag | 995.11 | –0.01 | –0.51 | –0.04 | –0.01 | –0.11 | –0.01 | –0.50 |
| ω12(a2) | asym. CH wag | 890.79 | 0.00 | 0.56 | 0.02 | 0.01 | 0.12 | 0.00 | 0.56 |
| ω13(a2) | ring twist | 378.44 | 0.01 | 0.01 | 0.06 | 0.01 | 0.02 | 0.01 | 0.01 |
| ω14(b1) | asym. CH wag | 996.87 | –0.69 | –0.41 | –0.11 | –0.06 | –0.06 | –0.15 | –0.16 |
| ω15(b1) | sym. CH wag | 953.64 | 0.02 | 0.12 | –0.02 | 0.01 | 0.03 | 0.12 | 0.12 |
| ω16(b1) | ring chair | 753.17 | –1.58 | 0.02 | 0.03 | –0.02 | –0.14 | 0.00 | –0.30 |
| ω17(b1) | sym. CH wag | 711.89 | 2.46 | 0.36 | 0.12 | 0.08 | 0.19 | 0.03 | 0.36 |
| ω18(b1) | ring boat | 409.22 | 0.21 | 0.01 | 0.03 | 0.00 | 0.00 | 0.03 | 0.01 |
| ω19(b2) | asym. CH str. | 3204.49 | –0.01 | –0.03 | –0.02 | 0.00 | –0.01 | 0.00 | –0.02 |
| ω20(b2) | asym. CH str. | 3168.42 | 0.00 | 0.03 | –0.04 | 0.00 | 0.01 | –0.01 | 0.00 |
| ω21(b2) | ring str. def. | 1618.43 | –0.50 | –0.46 | –0.01 | –0.04 | –0.03 | –0.25 | –0.48 |
| ω22(b2) | ring str. def. | 1464.66 | –1.02 | –6.46 | –0.10 | –0.17 | –0.18 | 0.17 | 0.06 |
| ω23(b2) | sym. CH wag | 1379.21 | –1.34 | –22.61 | –0.12 | –0.04 | –0.06 | 0.04 | 0.29 |
| ω24(b2) | ring str. def. | 1266.95 | 0.38 | 27.60 | –0.37 | –18.15 | –1.56 | –0.01 | –1.05 |
| ω25(b2) | asym. CH wag | 1158.82 | 2.50 | 4.87 | 0.75 | 19.79 | 2.00 | 0.02 | 1.30 |
| ω26(b2) | ring str. def. | 1071.35 | 0.65 | 0.07 | 0.07 | 0.05 | 0.02 | 0.09 | 0.07 |
| ω27(b2) | ring shearing | 656.98 | 0.11 | 0.01 | 0.02 | 0.01 | 0.00 | 0.03 | 0.01 |
a
ξ cutoff = 0.015, η = 74%, and n = 20 off-diagonals included.
b
ξ cutoff = 0.04, η = 22%, and n = 6 off-diagonals included.