The Hellmann potential in the J-matrix approach: II. Crossover phenomena and the radiative transition probabilities

We report the scaling properties of the bound state energies associated with the Hellmann potential using the Laguerre basis. We show the existence of a crossover phenomenon for the energy spectrum; the transition scaling for bound states to the continuum is a 'first order phase transition' as we approach the continuum. The method has potential applicability in predicting stable and metastable atomic and molecular states. Close to the bound-resonance crossover region, state energies and wavefunctions for the Hellmann potential have been studied. The average oscillator strength, multipole moments and radiative transition probabilities for certain states have been reported for future comparison.