MRCI study on potential energy curves and spectroscopic properties of HF molecule

The potential energy curves of the low-lying electronic states of Hydrogen fluoride (HF) have been investigated by using multireference configuration interaction (MRCI) approach in combination with cc-pV5Z basis sets for H and aug-cc-pV6Z basis sets for F. Three singlet states (X(1)Σ(+),B(1)Σ(+), 1(1)Δ), two triplet valence states ((3)ΠV,(3)ΣV(+)) and five triplet Rydberg states ((3)ΣR1(+),(3)ΠR1,(3)ΔR1,(3)ΣR1(-),(3)ΠR2) of HF molecular are identified. (3)ΠV and (3)ΣV(+) states are repulsive, the spectroscopic parameters (De, Re, ωe, Be and Te) of the bound states are derived in the present work. We find that the order of energy levels of (3)ΣR1(+),(3)ΠR1,(3)ΔR1 electronic states is different with other literatures, (3)ΣR1(+) is the lowest in these three states, which undergoes a strongly avoided crossing with the valence state (3)ΣV(+). The (3)ΣR1(-) state is studied at the first time. In addition, the dipole moments (DM), transition dipole moments (TDM), Einstein coefficients (Av'v'') , Franck-Condon factors (qv'v'') and radiative lifetime (τv') for B(1)Σ(+)-X(1)Σ(+) systems are predicted.