Chemical Physics Letters, Vol.397, No.1-3, 194-199, 2004
Spectroscopy and thermodynamics of LiS/NaS (X-2 Pi and A(2)Sigma(+)) and LiS+/NaS+(X-3 Sigma(-) and A(3)Pi)
Potential energy curves are calculated for the X(2)Pi and A(2)Sigma(+), states of LiS and NaS and the X(3)Sigma(-) and A(3)Pi states of LiS+ and NaS+. The RCCSD(T)/aug-cc-pVXZ levels of theory are employed (X = Q, 5 and infinity), where the infinityZ results are obtained at each bond distance, R, employing a two-point extrapolation to the basis set limit. From the three sets of curves, spectroscopic constants, ionization and dissociation energies are derived. Comparison is made to available experimental and calculational results. (C) 2004 Elsevier B.V. All rights reserved.