Ab initio study of NaRb: Potential energy curves, spectroscopic constants and atomic polarizabilities

Using an ab initio approach involving a non-empirical pseudopotentials for Na and Rb atoms, the adiabatic potential energy curves of 26 electronic states of NaRb ionic molecule dissociating up to Na(4p) + Rb and Na + Rb(7s) have been investigated. Their molecular spectroscopic constants have been derived and compared with the available theoretical works. Furthermore, the transition dipole moments from XR and 2R to higher excited states have been determined. Numerous avoided crossings between electronic states of R and P symmetries have been localised and analysed. Their existences are related to the charge transfer process between the two ionic systems NaRb and NaRb. The accurate potential energy curves have been exploited to realize a long-range vibrational level spacing analysis using the WKB semi-classical approximation in order to extract the Na and Rb atomic static dipole polarizabilities. A very good agreement between our static dipole polarizabilities and the available experimental and theoretical works has been observed. 2007 Elsevier B.V. All rights reserved.