Institute for Modelling and Innovative Technology, IMIT, Corrientes, Argentina.
J Chem Phys. 2018 Jan 28;148(4):044113. doi: 10.1063/1.5017986.
Several issues concerning Breit correction to electron-electron interaction in many-electron systems, which are important in precise atomic and molecular calculations, are presented. At first, perturbative versus self-consistent calculations of Breit correction were studied in selected cases. Second, the Z-dependence of Breit contribution per subshell is shown, based on values calculated for selected atoms with 30 ≤ Z ≤ 118. Third, the relations between magnetic and retardation parts of Breit interaction are analyzed. Finally, Gaunt contribution calculated for Kr, Xe, and Rn noble gas atoms and its iso-electronic HBr, HI, and HAt diatomic molecules has been compared to full-Breit atomic calculations. We found that Breit corrections should be treated by self-consistent calculations and that there is a functional dependence of those corrections for subshells as ε(Z)≃a×Z. We also found that molecular Gaunt corrections are close to their atomic counterparts for inner electrons though they are not for outer orbitals. In any case, accurate calculations must include retardation correction in addition to Gaunt.
介绍了多电子体系中电子-电子相互作用的 Breit 修正的几个问题，这些问题在精确的原子和分子计算中非常重要。首先，在选定的情况下研究了 Breit 修正的微扰与自洽计算。其次，基于对 30≤Z≤118 范围内选定原子的计算，展示了 Breit 贡献相对于每个子壳层的 Z 依赖性。第三，分析了 Breit 相互作用的磁部分和延迟部分之间的关系。最后，比较了 Kr、Xe 和 Rn 惰性气体原子以及与其等电子的 HBr、HI 和 HAt 双原子分子的 Gaunt 贡献与全 Breit 原子计算。我们发现 Breit 修正应该通过自洽计算来处理，而且这些修正对于子壳层存在函数依赖性，即 ε(Z)≃a×Z。我们还发现，尽管对于外层轨道而言不是这样，但对于内电子，分子 Gaunt 修正与其原子对应物非常接近。在任何情况下，除了 Gaunt 修正之外，精确计算还必须包括延迟修正。
