Electronic Absorption Spectra of the RbAr Van der Waals Complex

The potential energy curves of the ground state and many excited states of the RbAr van der Waals complex have been determined using [Rb+] and [e-Ar] pseudopotentials with the inclusion of core polarization operators on both atoms. This has reduced the number of active electrons of the RbAr system to only one valence electron, permitting the use of large basis sets for both the Rb and Ar atoms. Potential energy curves of the ground state and many excited states have been calculated at the SCF level. The core-core interactions for Rb+ Ar are included using the accurate CCSD potential of Hickling et al [Hickling, H.; Viehland, L.; Shepherd, D.; Soldan, P.; Lee, E.; Wright, T. Phys. Chem. Chem. Phys. 2004, 6, 4233]. Spectroscopic constants for the ground and excited states of RbAr are derived and compared with the available theoretical and experimental results. Furthermore, we have predicted the X-2 Sigma(+)---A(2)Pi(1/2), X-2 Sigma(+)---A Pi(3/2) and X-2 Sigma(+)--B-2 Sigma(+)(1/2) absorption spectra.