Classical trajectories of diatomic system H₂ and O₂ are calculated by means of symplectic algorithms in Murrell Sorbie diatomic potential. The results have been compared with the experiment and theory, and show that the classical trajectories are quite glossy.

The variation perturbation scheme based on hydrodynamic analogy to Schrödinger equation is adopted and the perturbed wavefunction for He atom in the ground state in a small and time dependent harmonic electric field and the polarizabilities and 1 st resonance frequency are calculated. Comparisons between the calculated results and experimental ones are also given.

In this paper as continuation of our first paper [4], the variational perturbation scheme based on hydrodynamic analogy to Schrödinger equation is adopted and the perturbed wavefunctions for the hydrogen-like atoms H, He⁺, Li⁺², Be⁺³,B⁺⁴ in their excited states (21±1)and (32±2)in a small and time harmonic electric field and the polarizabilities and the 1st resonant frequences are calculated. And the variation of the electronic probability is also discussed. It is shown that the calculated results of the polarizability and the 1st resonant frequence are in good agreement with the exact data. And it is further shown that ∈ and S play the same important role in the calculation of the polarizability using this scheme.

In this paper the variational perturbation scheme based on hydrodynamic analogy to Schrödinger equation is adopted and the perturbed wavefunctions for the hydrogen-like atoms H, He⁺, Li⁺², Be⁺³,B⁺⁴ in their ground state (100)in a small and time harmonic electric field and the polarizabities and the 1st resonant frequences are calculated. And the variation of the electronic probability with time is also discussed. It is shown that the calculated results of the polarizability and the 1st resonant frequence are in good agreement with the exact data and that ∈ and S play the same important role in the calculation of the polarizability by using this scheme.