| C6 | C8 | C10 | Ref. |
|---|---|---|---|
| 2.519[4] | 5.418[6] | 1.650[9] | M. Marinescu and A. Dalgarno, Phys. Rev. A 52, 311 (1995) |
| 2.517[4] | 5.580[6] | n/a | B. Bussery and M. Aubert-Frecon, J. Mol. Spectrosc. 115, 169 (1986) |
| 2.511[4] | 5.376[6] | 1.606[9] | F. Vigne-Maeder, Chem. Phys. 85, 139 (1984) |