Eur. Phys. J. D (2016) 70: 2
https://doi.org/10.1140/epjd/e2015-60228-y

Regular Article

Transition dipole function and radiative lifetimes for the A and C ¹Σ⁺ states of the LiH molecule

¹ Laboratoire des Interfaces et Matériaux Avancés, Faculty of Science, University of Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
² Mathematics and Natural Sciences Department, School of Arts and Sciences, American University of Ras Al Khaimah, Ras Al Khaimah, UAE
³ Laboratoire de Physique et Chimie Quantique, UMR 5626 du CNRS, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 4, France

^a e-mail: hamid.berriche@fsm.rnu.tn

Received: 13 April 2015
Received in final form: 30 September 2015
Published online: 12 January 2016

Abstract

The transition dipole moments of the first eight ¹Σ⁺ states of the LiH molecule have been calculated using ab initio approach based on the pseudopotential technique. Such transition dipole moments have been used to determine the radiative lifetimes for all vibrational levels of the first and the second excited states, A and C ¹Σ⁺, using accurate adiabatic potential energy curves. In addition to the bound-bound transitions, we have included the bound-free emissions probabilities. The latter was calculated exactly and using the Franck-Condon approximation and then included in the total radiative lifetime. A significant change in these lifetimes has been observed, particularly for the higher excited vibrational levels for which the approximate evaluation breaks down. The radiative lifetimes of the vibrational levels of the A¹Σ⁺ exited sate are in very good agreement with the few available theoretical and experimental results. However, the radiative lifetimes associated to the C¹Σ⁺ state are presented here for the first time.