Ionic Kratzer bond theory and vibrational levels for achiral covalent   bond HH
  A dihydrogen Hamiltonian reduces to the Sommerfeld-Kratzer-potential, adapted for field quantization according to old-quantum theory. Constants omega_e, k_e and r_e needed for the H_2 vibrational system derive solely from hydrogen mass m_H. For H_2, a first principles ionic Kratzer oscillator returns the covalent bond energy within 0,08 % and all levels within 0,02 %, 30 times better than the Dunham oscillator and as accurate as early ab initio QM. 
G. Van Hooydonk