Abstract
Based on a series of ab initio calculations two Feshbach resonances of the H − 3 negative ion having λ(1 sa′1)2(2sa′1)2−μ(1sa′1)2(2pa′′2)2: 1 A′1 and (1sa′1)2(2sa′1)(2pa′′2): 3 A′′2 electronic structure and estimated lifetimes of more than 10−14 s are predicted. The potential energy surfaces of the Feshbach states are roughly parallel to those of the Rydberg states of neutral H 3 and show minima located between the dissociative 2pE′ ground state surfaces and the lowest Rydberg states 2sA′1 and 2pA′′2 of H 3. We have determined a number of vibrational levels of the non-rotating molecules H − 3 and D − 3 and we predict electron affinities for the mentioned two Rydberg states.
Acknowledgements
The authors thank the Ernst Miescher Foundation (Basel, Switzerland) for technical support.
Notes
a For H 3 the non-rotating (J = 0) vibration level with v 1 = v 2 = 0. is Pauli-forbidden.
bwith respect to the minimum at −1.49892 a.u. for r HH = 1.605 a o .
cwith respect to the minimum at −1.49665 a.u. for r HH = 1.621 a o .
dwith respect to the minimum at −1.48382 a.u. for r HH = 1.603 a o .
ewith respect to the minimum at −1.47822 a.u. for r HH = 1.642 a o .
ffrom Ref. [Citation32].
1. 2003 Wang et al. [Citation11] reported to have observed H − 3.
2. With a basis containing one set of f functions added on the H atoms we obtain −1.48357 a.u. and −1.47845 a.u., respectively.
3. An electronic copy of Ref. [30] can be obtained from the author.
4. Essential of course for the reduced symmetries C 2 v and C s , not for D 3h .
5. Neutralisation of the triplet Feshbach state by the dissociative third valence state 4 A′2 can be ruled out because its PES is much higher in the reference region.