Eur. Phys. J. D (2017) 71: 3
https://doi.org/10.1140/epjd/e2016-70415-y

Regular Article

Relativistic rotation-vibrational energies for the Cs₂ molecule

¹ State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, P.R. China
² China Huanqiu Contracting and Engineering Corporation, Beijing 100012, P.R. China

^a e-mail: chshjia@263.net

Received: 28 June 2016
Received in final form: 25 September 2016
Published online: 10 January 2017

Abstract

We present bound state solutions of the Dirac equation with the improved Rosen-Morse potential energy model. In the non-relativistic limit, the relativistic energy equation becomes the non-relativistic rotation-vibrational energy expression of the diatomic molecule. We find that the relativistic effect of the relative motion of the ions produces an obvious decrease in the vibrational energies for the 3³Σ_g⁺ state of the Cs₂ molecule. It is observed that the behavior of the relativistic rotation-vibrational energies in larger rotational quantum numbers remains similar to that of the system with zero rotational quantum number.