High-correlation methods for the calculations of the ground (X1Σ+) and first low-lying excited (A 3Σ+ and A 1Σ+) states dipole polarizabilities of NaLi

The dipole polarizability of the ground X 1Σ+ and excited A 3Σ+, A 1Σ+ states of NaLi has been investigated at the ab initio level with effective core polarization potentials, by using the time-dependent gauge invariant method (TDGI). In the case of X 1Σ+ and A 3Σ+ states, alternative high-correlation methods have been applied for comparison. The accuracy of calculated polarizability components is supported by a careful check of the convergence with respect to the number of the spectroscopic states. The dependence of the polarizability on internuclear separation has also been computed. All the calculated electric properties of A 3Σ+ and A 1Σ+ excited states are new.