| TABLE 4. Selected properties of methanol computed by Hartree Fock ab initio methods | ||||||||||||
| Hartree Fock | Basis | Geometrical values | Vibrational values | Thermodynamic values/Hartrees | Dipole | |||||||
| Basis Sets | Func's | R(C-O) /Å |
A(C-O-H) /degrees |
R(O-H) /Å |
v(C-O)/cm-1 I(IR) |
v(O-H)/cm-1 I(IR) |
Ezp | Eth | Eth+e | Ee | moment /Debye |
|
| I(Raman) | I(Raman) | |||||||||||
| 1 | 6-31G(d) | 38 | 1.3994 | 109.5 | 0.9464 | 1189 |
4117.2 |
0.055332 | 0.05859 | -114.976828 | -115.035418 | 1.8651 |
| 2 | 6-31+G(d) | 46 | 1.4015 | 110.4 | 0.9463 | 1178.3 |
4119.1 |
0.055193 | 0.055193 | -114.982495 | -115.037688 | 1.9985 |
| 3 | 6-31G(d,p) | 50 | 1.3987 | 109.6 | 0.9462 | 1188.3 |
4193.9 |
0.05513 | 0.058398 | -114.988312 | -115.04671 | 1.8342 |
| 4 | 6-31++G(d) | 50 | 1.4016 | 110.4 | 0.9465 | 1177.6 |
4116.4 |
0.055165 | 0.058444 | -114.982681 | -115.041125 | 1.9915 |
| 5 | 6-311+G(d) | 56 | 1.3988 | 110.8 | 0.9393 | 1177.5 |
4176.1 |
0.055073 | 0.05835 | -115.009983 | -115.068333 | 2.0206 |
| 6 | 6-31+G(d,p) | 58 | 1.4016 | 110.4 | 0.942 | 1176.5 |
4202.2 |
0.055165 | 0.058444 | -114.982681 | -115.041125 | 1.9915 |
| 7 | 6-31++G(d,p) | 62 | 1.4012 | 110.6 | 0.942 | 1175.9 |
4200.7 |
0.054973 | 0.058269 | -114.994245 | -115.052514 | 1.9669 |
| 8 | 6-311++G(d,p) | 72 | 1.4001 | 110 | 0.9396 | 1173 |
4192.9 |
0.054764 | 0.05806 | -115.022448 | -115.080508 | 1.9388 |
| 9 | 6-311++G(2d,2p) | 94 | 1.4001 | 110.1 | 0.928 | 1155.0 |
4198.9 |
0.05482 | 0.058137 | -115.027514 | -115.085651 | 1.7959 |
| 10 | 6-311++G(3df,3pd) | 150 | 1.3974 | 110.3 | 0.9383 | 1172.7 |
4184.5 |
0.054678 | 0.057992 | -115.032575 | -115.090567 | 1.7408 |
| TABLE 5 Comparison of experimental and calculated normal modes of methanol (cm-1) by three ab initio methods at two basis sets | |||||||||||||
| Measured | Calculated HF/ 6-31G(d) |
shift |
Calculated MP2/ 6-31G(d) |
shift |
Calculated B3LYP/ 6-31G(d) |
shift |
Calculated HF/ 6-311++G 3df,3pd) |
shift |
Calculated MP2/ 6-311++G (3df,3pd) |
shift |
Calculated B3LYP/ 6-311++G (3df,3pd) |
shift |
|
| 1 | 271.5 | 347.2 | -75.7 | 356.6 | -85.1 | 347.7 | -76.2 | 302.7 | -31.2 | 292.8 | -21.3 | 285.3 | -13.8 |
| 2 | 1033.5 | 1164.1 | -130.6 | 1083.9 | -50.4 | 1068.7 | -35.2 | 1151.9 | -118.4 | 1063.5 | -30 | 1044.5 | -11 |
| 3 | 1074.5 | 1189 | -114.5 | 1113.1 | -38.6 | 1097.9 | -23.4 | 1172.7 | -98.2 | 1093.9 | -19.4 | 1077.9 | -3.4 |
| 4 | 1145 | 1290.1 | -145.1 | 1203.9 | -58.9 | 1183.7 | -38.7 | 1279.5 | -134.5 | 1188.8 | -43.8 | 1173 | -28 |
| 5 | 1334 | 1507.1 | -173.1 | 1418.5 | -84.5 | 1400.6 | -66.6 | 1478.3 | -144.3 | 1372.5 | -38.5 | 1366.2 | -32.2 |
| 6 | 1454.5 | 1637.7 | -183.2 | 1539.2 | -84.7 | 1511.8 | -57.3 | 1608.9 | -154.4 | 1498 | -43.5 | 1480.4 | -25.9 |
| 7 | 1465 | 1651.7 | -186.7 | 1565 | -100 | 1524.9 | -59.9 | 1620.6 | -155.6 | 1524.9 | -59.9 | 1497.4 | -32.4 |
| 8 | 1473 | 1663.5 | -190.5 | 1578.4 | -105.4 | 1541.9 | -68.9 | 1629.4 | -156.4 | 1536.1 | -63.1 | 1509.5 | -36.5 |
| 9 | 2844.2 | 3184.5 | -340.3 | 3074.9 | -230.7 | 2995 | -150.8 | 3140.4 | -296.2 | 3052.7 | -208.5 | 2924.2 | -80 |
| 10 | 2970 | 3230.5 | -260.5 | 3141.8 | -171.8 | 3037 | -67 | 3184.2 | -214.2 | 3126.6 | -156.6 | 3041.4 | -71.4 |
| 11 | 2999 | 3305.2 | -306.2 | 3221.7 | -222.7 | 3130.7 | -131.7 | 3247.5 | -248.5 | 3186.1 | -187.1 | 3111.4 | -112.4 |
| 12 | 3756 | 4117.2 | -361.2 | 3970.7 | -214.7 | 3750.8 | 5.2 | 4184.5 | -428.5 | 3909.8 | -153.8 | 3846.2 | -90.2 |
| Average shift | -205.6 | -120.6 | -64.2 | -181.7 | -85.5 | -44.8 | |||||||