In this paper, the variational quantum Monte Carlo method is applied to investigate the ground state of the lithium atom. Moreover, the energy eigenvalues of the lithium atom in dense plasma are also investigated by using the Debye–Hückel model and the exponential cosine screened Coulomb potential model. The calculations are carried out by using trial wave functions in the form of the Slater determinant wave function multiplied by a correlation function due to the interaction between the electrons. Three types of correlation functions are used—with two, three and four variational parameters—one of which satisfies the well-known cusp conditions. Interesting results are obtained in comparison with results obtained by using other trial wave functions.

本文采用变分蒙特卡罗方法研究了锂原子的基态。此外，还使用Debye-Hückel模型和指数余弦筛选的库仑势模型研究了稠密等离子体中锂原子的能量本征值。由于电子之间的相互作用，使用斯拉特行列波函数乘以相关函数的形式的试验波函数来进行计算。使用了三种类型的相关函数-具有两个，三个和四个变化参数-其中一个满足众所周知的尖峰条件。与使用其他试波函数获得的结果相比，获得了有趣的结果。