Ab initio potential energy curves and transition dipole moments for the interaction of a ground state He with Na(3s–3p)

Excitation of Sodium Atoms Attached to Helium Nanodroplets: The 3p ← 3s Transition Revisited

“…For the required excited state NaHe pair potentials, we have used three different sets of potentials: the well-known pseudopotentials of Pascale, 57 the recent model potentials of Mullamphy et al, 68 and the ab initio potentials of Allouche and co-workers. 69 The latter are very similar to those of Dell'Angelo et al 23 but have been calculated for larger internuclear distances. The three sets of potentials mainly differ in terms of the well depth for the Π state and the long-range behavior of the Σ state.…”

“…Next the Π and Σ excited state potential energy curves were obtained within the diatomics in molecules (DIM) approach by averaging the corresponding matrix elements over the ground state helium density. For the required excited state NaHe pair potentials, we have used three different sets of potentials: the well-known pseudopotentials of Pascale, the recent model potentials of Mullamphy et al, and the ab initio potentials of Allouche and co-workers . The latter are very similar to those of Dell’Angelo et al but have been calculated for larger internuclear distances.…”

“…As illustrated in the upper panel of Figure 9, the 2 Σ 1/2 and 2 Π 1/2 model potentials based on the NaHe pair potentials of Mullamphy et al 68 cross at certain distances. For the sake of 69 (lower panel). The zero for energy is defined as the spin-free dissociation limit He 1000 + Na 2 P. demonstration, the well depths of the potentials in this figure have been artificially enlarged.…”

“…Figure 8. Calculated energy dependence of the state-specific absorption cross sections (solid lines) and anisotropy parameters (dashed lines) for Na@He 1000 based on the NaHe pair potentials of Mullamphy et al68 (upper panel), Pascale57 (middle panel), and Allouche et al69 (lower panel). The zero for energy is defined as the spin-free dissociation limit He 1000 + Na 2 P.…”

Excited Li and Na in Hen: Influence of the dimer potential energy curves

“…For Na, the cc-pV5Z basis set which contains (23s,16p,8d,6f,4g,2h) Gaussian functions contracted into [11s,10p,8d,6f,4g,2h] is used. Allouche et al 49 showed that the cc-pV5Z basis set yields accurate results, in particular for the well depth D e and the minimum position R e values for the A 2 state when compared with available experimental data. 50 Furthermore, only the inner 1s orbital of Na is treated as frozen in the CASSCF and MRCI calculations, leaving 11 electrons for which correlation effects are fully taken into account.…”