Table 1. Vibrational Frequencies for trans-Ethanola.
| mode | scl-harm (ref (77))b | scl-harm (ref (76))c | MM (11 modes) | MM (15 modes) | AS SCIVR | expt (ref (77)) |
|---|---|---|---|---|---|---|
| 7(CO–str) | 1090 | 1093 | **** | 1101 | 1088 | 1090 (1093) |
| 8(CH2–rck) | 1160 | 1150 | **** | 1160 | 1148 | 1166 |
| 9(COH–bnd) | 1248 | 1251 | **** | 1251 | 1242 | 1241 (1245) |
| 10(CH2–twst) | 1268 | 1269 | **** | 1276 | 1271 | 1275 |
| 11(CH3–sdef) | 1375 | 1375 | 1367 | 1370 | 1363 | 1367 |
| 12(CH2–wag) | 1431 | 1423 | 1427 | 1426 | 1420 | 1450 (1430) |
| 13(CH3–adef′) | 1455 | 1458 | 1444 | 1443 | 1440 | 1455 |
| 14(CH3–adef″) | 1472 | 1476 | 1459 | 1459 | 1456 | 1480 (1460) |
| 15(CH2–sdef) | 1503 | 1500 | 1491 | 1489 | 1481 | 1500 (1460) |
| 16(CH2–sstr) | 2872 | 2865 | 2810d | 2811d | 2881 | 2888 (2887) |
| 17(CH2–astr) | 2912 | 2887 | 2864d | 2884d | 2888 | 2901 |
| 18(CH3–sstr) | 2926 | 2941 | 2939d | 2937d | 2933 | 2922 |
| 19(CH3–astr″) | 3012 | 3011 | 2976d | 2977d | 2983 | 2987 |
| 20(CH3–astr′) | 3022 | 3014 | 2978d | 2981d | 2986 | 2992 |
| 21(OH–str) | 3585 | 3678 | 3679 | 3672 | 3676 | 3676 (3675) |
| MAE | 13 | 12 | 19 | 13 | 8 |
a
Harmonic, MULTIMODE (4MR), AS SCIVR, and experimental IR and Raman gas values. Numbers in parentheses are from Raman experiment. MAE is the mean absolute error with respect to the closest experimental frequency.
b
Scaled harmonic at MP2/6-31G(d) level. Scaling factors: 1.0 for heavy atom bend; 0.88 for CH stretches (str) and deformations (def); 0.90 for all other modes.
c
Scaled harmonic at DFT/B97-3c level. Scaling factor 0.979.