The Hamiltonian of sodium atom is reduced by using screening Coulombpotential, and the energy levels of sodium atom are calculated by means of twofold perturbation.
用屏蔽库仑势简化了钠原子的哈密顿，用两次微扰法计算了钠原子的能量，结果与实验值符合得较好。
2
The ground state energy, the vibrational frequency and the mean number of optical phonons are expressed as a function of the confinement strength of quantum wire and the Coulomb bound potential.