QUASI-DIABATIC AND ADIABATIC STATES AND POTENTIAL-ENERGY CURVES FOR NA-CD COLLISIONS AND EXCIMER FORMATION

We present the ab initio calculation of potential energy curves for th e ground and excited electronic states of the NaCd system. Both quasi- diabatic and adiabatic wavefunctions and energies have been determined , by means of Quasi Degenerate Perturbation Theory (CIPSI algorithm). The spin-orbit coupling has been evaluated with two approximate method s: one is based on effective nuclear charges, the other one exploits t he quasi-invariance of the diabatic states with respect to changes in the nuclear coordinate. The present results are relevant as to the int erpretation of the emission spectra of the excimer NaCd, and to the c ollisional dynamics of excited Na and Cd atoms.