| C3 | C6 | C8 | Ref. |
|---|---|---|---|
| 8.436(0.014) | 6.272(0.094)[3] | n/a | H. Wang, P. L. Gould, and W. C. Stwalley, J. Chem. Phys. 106, 7899 (1997) |
| 8.665 | 6.291[3] | 2.893[5] | M. Marinescu and A. Dalgarno, Phys. Rev. A 52, 311 (1995) |
| 9.340 | 6.868[3] | -3.734[4] | B. Bussery and M. Aubert-Frecon, J. Chem. Phys. 82, 3224 (1985) |
| 8.768 | 6.465[3] | 2.624[5] | F. Vigne-Maeder, Chem. Phys. 85, 139 (1984) |