用模型势方法和斯莱特-高登(Slater-Condon)理论计算了钡原子偶宇称6s~2,5d~2,6p~2电子组合、角动量J=0,1,2的双激发能级的激发能和组合相互作用(configuration interaction)。结果表明,6s~2,5d~2和6p~2组合在~1S_0态中强烈地混合,使常规能级标识符号失去意义。另外,我们的结果也从理论上证明了曾引起争议的6p~(21)S_0能级是位于第一电离势之上的自由离能级。

Configuration admixture and excitation energies are computed for the even-parity J=0, 1, 2, valent states of 6s2, 5d2 and 6pa confiqurations of Ba. We employ a model potential method to obtain the one-electron spin-orbitals. The computed excitation energies are generally in good agreement with available experimental data, and the three configurations are found to admix heavily in the 1S0 states. The results also identify theoretically 6p2 1S0 autoionizing state which gave rise to controversy in assignments of the levels of Ba.