Table 2.
The A-A’ atomic energies (kJ/mol) of various Methyl groups (columns 2 to 6) in different molecules calculated with the (15,15) grid. Columns 7 to 11 list the energy differences with reference molecule ethane. The H1 atom is the one lying in a plane, if such a plane exists. The energy values for the other two hydrogens have been averaged if there is global symmetry in the compound. Two different total average values are given in the last two rows, with the standard deviation in brackets. Method: 2PDM-M/CCSD(T)/uncontracted 6–31 + G(d, p). The sum in the utmost right column is a sum of the absolute differences. If more than one Methyl group is present in a molecule, then the Methyl referred to is marked in bold
| Molecule | C of CH3 | H1 | H2 | H3 | sum | C of CH3 | H1 | H2 | H3 | sum |
|---|---|---|---|---|---|---|---|---|---|---|
| CH4 | 74.2 | 26.6 | 26.6 | 26.6 | 154.1 | −13.0 | −3.2 | −3.2 | −3.2 | 22.7 |
| C2H6 (reference molecule) | 87.2 | 29.9 | 29.9 | 29.9 | 176.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| C3H8 (asym)a | 89.9 | 31.1 | 30.3 | 30.3 | 181.5 | 2.7 | 1.2 | 0.4 | 0.4 | 4.8 |
| C3H8 (sym)a | 89.8 | 31.1 | 30.3 | 30.3 | 181.5 | 2.6 | 1.2 | 0.4 | 0.4 | 4.7 |
| C4H10 (n-butane) | 90.7 | 31.6 | 30.6 | 30.6 | 183.6 | 3.5 | 1.8 | 0.7 | 0.7 | 6.8 |
| CH3NH2 | 90.6 | 30.7 | 30.0 | 30.0 | 181.3 | 3.5 | 0.9 | 0.1 | 0.1 | 4.5 |
| C2H5NH2 | 90.5 | 31.1 | 30.3 | 30.5 | 182.3 | 3.3 | 1.3 | 0.4 | 0.6 | 5.6 |
| C3H7NH2 | 91.4 | 31.6 | 30.8 | 30.7 | 184.5 | 4.2 | 1.8 | 0.9 | 0.9 | 7.8 |
| iso-C3H7NH2 | 92.4 | 31.5 | 31.5 | 30.6 | 186.0 | 5.3 | 1.7 | 1.6 | 0.7 | 9.2 |
| CH3SH | 93.0 | 30.5 | 30.9 | 30.9 | 185.4 | 5.9 | 0.6 | 1.0 | 1.0 | 8.6 |
| CH3SCH3 | 95.2 | 31.6 | 31.2 | 31.2 | 189.2 | 8.0 | 1.7 | 1.4 | 1.4 | 12.5 |
| CH3CO2H | 96.1 | 30.9 | 31.7 | 31.7 | 190.4 | 8.9 | 1.0 | 1.8 | 1.8 | 13.6 |
| CH3OH | 92.9 | 29.5 | 30.3 | 30.3 | 183.0 | 5.7 | −0.4 | 0.5 | 0.5 | 7.0 |
| C2H5OH | 89.8 | 30.8 | 30.1 | 30.1 | 180.8 | 2.7 | 0.9 | 0.2 | 0.2 | 4.0 |
| C3H7OH | 91.0 | 31.4 | 30.7 | 30.7 | 183.7 | 3.8 | 1.6 | 0.8 | 0.8 | 6.9 |
| iso-C3H7OH | 92.8 | 31.3 | 31.3 | 30.5 | 186.0 | 5.7 | 1.5 | 1.5 | 0.7 | 9.3 |
| CH3CONH2 | 97.2 | 30.9 | 32.0 | 32.0 | 192.2 | 10.1 | 1.0 | 2.2 | 2.2 | 15.4 |
| CH3CHO | 95.9 | 30.1 | 31.6 | 31.6 | 189.2 | 8.8 | 0.2 | 1.7 | 1.7 | 12.4 |
| CH3CH2CHO | 91.5 | 31.7 | 30.8 | 30.8 | 184.9 | 4.3 | 1.8 | 1.0 | 1.0 | 8.1 |
| n-C3H7CHO | 92.2 | 31.9 | 31.1 | 31.1 | 186.4 | 5.0 | 2.1 | 1.2 | 1.2 | 9.6 |
|
iso-CH3C(H)(CH3)CHO cis to O |
93.4 | 32.0 | 31.2 | 31.7 | 188.3 | 6.2 | 2.1 | 1.3 | 1.9 | 11.6 |
| iso-CH3C(H)(CH3)CHO gauche to O | 94.3 | 32.0 | 31.3 | 31.9 | 189.5 | 7.1 | 2.2 | 1.4 | 2.0 | 12.8 |
| CH3COCH3 | 97.5 | 31.0 | 31.9 | 31.9 | 192.2 | 10.3 | 1.1 | 2.0 | 2.0 | 15.4 |
| CH3COCH2CH3 | 98.3 | 31.6 | 31.9 | 32.4 | 194.2 | 11.2 | 1.7 | 2.0 | 2.5 | 17.4 |
| CH3COCH2CH3 | 92.4 | 32.1 | 31.0 | 31.1 | 186.7 | 5.2 | 2.2 | 1.2 | 1.3 | 9.9 |
| CH3NH3+ | 89.4 | 27.9 | 27.9 | 27.9 | 173.1 | 2.2 | −2.0 | −2.0 | −2.0 | 8.1 |
| CH3NH3+.H2O | 89.4 | 28.7 | 28.4 | 28.4 | 174.8 | 2.2 | −1.1 | −1.5 | −1.5 | 6.3 |
| CH3NH3+.(H2O)2 | 89.3 | 28.6 | 28.9 | 28.9 | 175.6 | 2.1 | −1.3 | −1.0 | −1.0 | 5.4 |
| CH3OCH3 | 95.8 | 30.9 | 30.9 | 30.9 | 188.4 | 8.7 | 1.0 | 1.0 | 1.0 | 11.7 |
| CH3OCH2CH3 | 90.9 | 31.3 | 30.5 | 30.5 | 183.1 | 3.7 | 1.4 | 0.6 | 0.6 | 6.3 |
| CH3OCH2CH3 | 97.1 | 31.5 | 31.3 | 31.3 | 191.2 | 9.9 | 1.6 | 1.4 | 1.4 | 14.4 |
| (CH3-NH)C(NH2)NH2+ | 94.3 | 31.2 | 30.8 | 30.7 | 186.9 | 7.1 | 1.3 | 0.9 | 0.8 | 10.2 |
| CH3CON(H)CH3 | 98.0 | 31.3 | 32.4 | 32.4 | 194.1 | 7.8 | 2.0 | 1.7 | 1.7 | 13.4 |
| CH3CON(H)CH3 | 95.0 | 31.9 | 31.6 | 31.6 | 190.1 | 10.9 | 1.4 | 2.5 | 2.5 | 17.3 |
| C2H5CO2− | 96.2 | 33.9 | 32.3 | 31.6 | 194.0 | 9.1 | 4.0 | 2.4 | 1.7 | 17.2 |
| C2H5CO2H | 92.1 | 31.9 | 30.8 | 30.8 | 185.7 | 5.0 | 2.0 | 0.9 | 0.9 | 8.9 |
| CH3(H)C = C(CH3)2 | 94.6 | 32.1 | 32.2 | 32.2 | 191.0 | 9.2 | 1.9 | 2.8 | 2.8 | 16.7 |
| CH3(H)C = C(CH3)2 trans | 96.4 | 31.8 | 32.6 | 32.6 | 193.4 | 8.6 | 1.5 | 2.6 | 2.6 | 15.5 |
| CH3(H)C = C(CH3)2 cis | 95.8 | 31.4 | 32.5 | 32.5 | 192.2 | 7.5 | 2.2 | 2.3 | 2.3 | 14.3 |
| C2H5(H)C = CH2 | 92.5 | 32.1 | 31.0 | 31.1 | 186.7 | 5.4 | 2.2 | 1.2 | 1.2 | 9.9 |
| (CH3)2C=CH2 | 95.2 | 31.5 | 32.1 | 32.1 | 191.0 | 8.0 | 1.7 | 2.3 | 2.3 | 14.2 |
| CH3(H)C = C(H)CH3 trans | 94.2 | 30.9 | 32.3 | 32.3 | 189.8 | 7.1 | 1.1 | 2.5 | 2.5 | 13.1 |
| CH3(H)C = C(H)CH3 cis | 94.5 | 30.5 | 32.4 | 32.4 | 189.7 | 7.3 | 0.6 | 2.5 | 2.5 | 12.9 |
| CH3(H)C = CH2 | 97.0 | 32.2 | 32.2 | 32.2 | 193.4 | 9.8 | 2.3 | 2.3 | 2.3 | 16.7 |
| CH3C ≡ CCH3 | 96.9 | 32.4 | 32.4 | 32.4 | 194.1 | 9.7 | 2.5 | 2.5 | 2.5 | 17.4 |
| CH3C ≡ CCH2CH3 | 97.5 | 32.7 | 32.6 | 32.6 | 195.5 | 10.4 | 2.8 | 2.8 | 2.8 | 18.7 |
| CH3C ≡ CCH2CH3 | 93.0 | 32.5 | 31.2 | 31.2 | 187.8 | 5.9 | 2.6 | 1.3 | 1.3 | 11.1 |
| CH3CH2C ≡ CH | 93.2 | 32.3 | 31.1 | 31.1 | 187.7 | 6.1 | 2.4 | 1.2 | 1.2 | 11.0 |
| CH3CH2CH2C ≡ CH | 92.7 | 32.3 | 31.3 | 30.9 | 187.2 | 5.5 | 2.5 | 1.4 | 1.0 | 10.4 |
| CH3-C(H) = NH | 94.4 | 31.1 | 31.7 | 31.7 | 188.9 | 7.3 | 1.3 | 1.8 | 1.8 | 12.2 |
| CH3CH2C(H) = NH | 93.2 | 32.1 | 31.2 | 31.2 | 187.7 | 6.1 | 2.2 | 1.3 | 1.3 | 10.9 |
| CH3CH2CH2C(H) = NH | 92.6 | 32.3 | 31.2 | 31.2 | 187.3 | 5.5 | 2.4 | 1.3 | 1.3 | 10.6 |
| (CH3)2C=NH trans | 96.2 | 31.4 | 32.4 | 32.4 | 192.4 | 9.1 | 1.5 | 2.5 | 2.5 | 15.6 |
| (CH3)2C=NH cis | 97.0 | 31.5 | 32.4 | 32.4 | 193.3 | 9.8 | 1.6 | 2.5 | 2.5 | 16.5 |
| CH3C(H) = NCH3 | 95.3 | 31.7 | 32.1 | 32.1 | 191.3 | 8.1 | 1.8 | 2.3 | 2.3 | 14.5 |
| H3C(H) = NCH3 | 97.9 | 32.1 | 32.3 | 32.3 | 194.7 | 10.8 | 2.3 | 2.4 | 2.4 | 17.9 |
| H2C = NCH3 | 97.5 | 31.5 | 32.0 | 32.0 | 193.0 | 10.3 | 1.7 | 2.1 | 2.1 | 16.2 |
| CH3-C(H) = NCH2CH3 | 95.7 | 31.0 | 32.8 | 32.8 | 192.2 | 8.5 | 1.1 | 2.9 | 2.9 | 15.5 |
| CH3-C(H) = NCH2CH3 | 93.4 | 32.5 | 31.4 | 31.3 | 188.7 | 6.3 | 2.7 | 1.6 | 1.4 | 11.9 |
| CH3(C2H5)C = NH | 98.1 | 32.2 | 32.3 | 32.3 | 194.9 | 11.0 | 2.3 | 2.5 | 2.4 | 18.2 |
| CH3(CH2CH3)C = NH | 106.0 | 32.4 | 31.3 | 31.0 | 200.8 | 18.9 | 2.5 | 1.5 | 1.2 | 24.0 |
| Average (SD) include CH4 | 93.7 (4.0) | 31.3 (1.2) | 31.2 (1.2) | 31.2 (1.2) | 187.5 (6.9) | 6.6 (4.0) | 1.4 (1.2) | 1.3 (1.2) | 1.3 (1.2) | 11.9 (4.7) |
| Average (SD) exclude CH4 | 94.1 (3.1) | 31.4 (1.0) | 31.3 (1.0) | 31.3 (1.0) | 188.0 (5.4) |
6.9 (3.1) |
1.5 (1.0) | 1.4 (1.0) | 1.4 (1.0) | 11.7 (4.6) |
aThe symmetric form of C3H8refers to the conformation with (global) C2vsymmetry with the mirror plane containing the 3 carbons. The asymmetric form lacks any symmetry and is hence the point group is C1.