Electronic structure of spin-singlet and spin-triplet atomic carbon upon interaction with helium. A theoretical investigation

We present a theoretical investigation on the electronic structure of the C-He complex, either in the ground and in several spin-singlet and spin-triplet excited states. The interaction potentials have been computed at the MultiReference Configurations-Interaction level of theory. Our results compare well with best available data, which concern just the electronic ground state. We also determined the rovibrational bound states within a nonrelativistic approximation, and the transition dipole moments for electronic excitations. This study traces a coherent picture for the interaction of an excited carbon atom with helium, which is relevant in astrophysics and in a variety of terrestrial experiments.