| C3 | C6 | C8 | Ref. |
|---|---|---|---|
| -11.01 | 2.066[3] | 9.880[5] | M. Marinescu and A. Dalgarno, Phys. Rev. A 52, 311 (1995) |
| -11.02 | 1.927[3] | 1.124[6] | B. Bussery and M. Aubert-Frecon, J. Chem. Phys. 82, 3224 (1985) |
| -10.99 | 2.025[3] | 9.644[5] | F. Vigne-Maeder, Chem. Phys. 85, 139 (1984) |