Highly accurate calculations are reported for the eleven lowest states of the ² P Rydberg series (1s ² np ¹, n = 2, …, 12) of the lithium atom. The nonrelativistic wave functions of the states are expanded in terms of up to 16 000 all-electron explicitly correlated Gaussian (ECG) basis functions. The ECG exponential parameters are variationally optimized using a method that employs the analytical energy gradient determined for the parameters. The finite-nuclear-mass effects of the ⁶Li and ⁷Li isotopes are explicitly included in the nonrelativistic variational calculations. The results also include the leading relativistic and quantum electrodynamics energy corrections computed using the framework of perturbation theory. The calculated interstate transition energies are compared with the available experimental data. The ⁶Li–⁷Li isotope shifts of the transition energies are determined.

对锂原子的² P里德堡级数 (1 s ² np ¹ , n = 2, ..., 12)的 11 个最低状态报告了高度准确的计算。状态的非相对论波函数根据多达 16 000 个全电子显式相关高斯 (ECG) 基函数进行了扩展。使用采用为参数确定的分析能量梯度的方法对ECG 指数参数进行变分优化。⁶ Li 和⁷的有限核质量效应Li同位素明确包含在非相对论变分计算中。结果还包括使用微扰理论框架计算的领先的相对论和量子电动力学能量校正。计算的州际跃迁能量与可用的实验数据进行比较。确定了跃迁能的⁶ Li– ⁷ Li 同位素位移。