Table 7. Vibrational ground state rotational constants (in MHz) and centrifugal distortion constants corresponding to the symmetrically reduced Hamiltonian parameters (III r representation a ).
| CH 3CO | CH 2CHO | |||
|---|---|---|---|---|
| Calc. | Exp. b | Calc. | Exp. c | |
| A 0 | 84094.27 | 82946.73 | 66773.15 | 66677.85679(159) |
| B 0 | 9952.09 | 9955.46 | 11445.40 | 11447.0460(55) |
| C 0 | 9427.41 | 9426.95 | 9762.15 | 9758.9065(53) |
| Δ J | 0.009448 | 0.009422 | 0.0096468(22) | |
| Δ K | 2.756343 | 1.312964 | 1.307 | |
| Δ JK | 0.124574 | -0.084559 | -0.083045(137) | |
| d 1 | -0.000948 | -0.002006 | 0.0021215(101) | |
| d 2 | 0.000512 | -0.000129 | 0.0384(26) | |
| H J | 0.000041 | 0.000014 | ||
| H K | 0.897964 | 0.078700 | ||
| H JK | -0.001033 | -0.000287 | ||
| H KJ | -0.630725 | -0.006429 | ||
| h 1 | 0.000004 | 0.000007 | ||
| h 2 | -0.000014 | 0.000001 | ||
| h 3 | 0.000001 | 0.000000 | ||
| CH 3COCH 2 (calc) | ||||
| A 0 | 10949.35 | H J | 0.000024 | |
| B 0 | 9054.05 | H K | -0.000014 | |
| C 0 | 5110.78 | H JK | -0.000088 | |
| Δ J | 0.010134 | H KJ | 0.000078 | |
| Δ K | 0.004463 | h 1 | 0.000006 | |
| Δ JK | -0.013811 | h 2 | 0.000003 | |
| d 1 | -0.000763 | h 3 | 0.000002 | |
| d 2 | -0.000596 | |||
a) The z-axis was selected to coincide with the x-Eckart axis in CH 3CO and CH 2CHO, and with the z-Eckart axis in CH 3COCH 2.
b) The rotational constants of Ref. 14, to be compared with our results, are given in the Principal Axes System. They were determined from the A, (B±C)/2, and D values given in the Rho-Axes System after transforming them to the Principal Axes System.
c) Ref 15.