Electronic, spectra, and spin orbit interaction for FrAr van der Waals system

Abstract

The potential energy curves and spectroscopic constants of the ground and many excited states of the FrAr van der Waals system have been determined using a one-electron pseudopotential approach. The Fr þ core and the electron-Ar interactions are replaced by effective potentials. The Fr þ Ar corecore interaction is incorporated using the accurate CCSD(T) potential of Hickling et al. (Phys. Chem. Chem. Phys. 2004, 6, 4233). This approach reduces the number of active electrons of the FrAr van der Waals system to only one valence electron, which permits the use of very large basis sets for the Fr and Ar atoms. Using this technique, the potential energy curves of the ground and many excited states are calculated at the self consistent field (SCF) level. In addition, the spin-orbit interaction is also considered using the semiempirical scheme for the states dissociating into Fr (7p) and Fr (8p). The FrAr system is not studied previously and its potential interactions, spectroscopic constants and dipole functions are presented here for the first time. Furthermore, we have predicted the X 2 R þ -A 2 P 1/

Spectroscopic Properties of the Alkali–Krypton Diatomic M–Kr (M = Rb, Cs, and Fr) van der Waals Systems Including the Spin–Orbit Coupling

“…For each atom (λ = Rb, Fr, or Kr), the core polarization effects are described by the following effective potential: where λ is for either the M + (M = Rb, Cs, and Fr) core or the krypton atom, α is the dipole polarizability, and f is the electric field created by valence electrons and cores of each center. The used polarizabilities of the alkali ions were taken as 9.245 a 0 3 , 15.116 a 0 3 , and 20.38 a 0 3 for Rb, Cs, and Fr, respectively, − whereas that of the krypton atom was taken as 17.0 a 0 3 …”

“…Interactions of alkali metal atoms with rare gas atoms are of great importance in several areas of physics and chemistry. These interactions have been investigated experimentally − and theoretically − for many years and for many systems. In fact, they are considered as model systems for van der Waals molecules.…”

“…Theoretically, there are several calculations − of the interactions between the alkali atoms with noble gas atoms. The M­( 2 S) + Rg pairs (M = alkali; Rg = rare gas) were investigated by Baylis using pseudopotential method and spin–orbit coupling.…”

“…Goll et al studied the M–Rg (M = Li, Na, K, Rb, and Cs; Rg = Ar, Kr, and Xe) systems using the short-range gradient-corrected density functional method combined with long-range coupled-cluster methods (CCSD, CCSD­(T)). More recently, the van der Waals systems involving alkali and alkaline-earth atoms interacting with rare gas atoms have been investigated by our group − using a one-electron pseudopotential approach, large Gaussian basis sets, and full configuration interaction.…”

Enhanced quantum size effect in Li and Na clusters via rare gas doping

“…Na and Li are chemically active with each a nearly free electron. The chemical bond between rare gas and alkali metal is weak without chemical reaction taking place when interacted. However, there are great number of experiments about absorption and excitation spectroscopy of metals in rare gas matrices .…”