Multi-reference configuration interaction calculation of positronium fluoride 2,1S and 2,1P states

Abstract

Multi-reference configuration interaction calculations for the ground state 2,1S and an excited state 2,1P of positronium fluoride (PsF) were performed, and their energies, the positronium (Ps) binding energies and the two-photon positron-electron pair annihilation rates were presented. From an analysis of the convergence pattern of the total energies and the two-photon annihilation rates with respect to the angular momentum of basis functions, an extrapolation method which may give accurate Ps binding energies and two-photon annihilation rates was applied. Estimated Ps binding energy for 2,1S state of PsF was in good agreement with the recent reliable calculations. The structures of 2,1S and 2,1P states of PsF also were predicted from the point of view of the two-photon annihilation rate.