Theoretical investigation of the diatomic Van der Waals systems Ca+He and CaHe.

An ab initio investigation has been performed for the ground and several excited states of Ca + He and CaHe systems. The potential energy curves, spectroscopic constants, vibrational levels energies and electric dipole moments have been calculated and analyzed. The ab initio method uses the pseudo-potentials technique, Core Polarization Potentials (CPP) and Full Configuration Interaction (FCI). The number of active electrons of Ca + He and CaHe are reduced to one and two active electrons, respectively. The examination of these numerous results shows interesting structures and behaviors resulting from a collision-induced process that involves calcium and helium atoms. An excellent agreement is found with the available results which confirms the reliability of our calculation. [ABSTRACT FROM AUTHOR]