全相对论多组态原子结构及物理量的精密计算——构建准完备基以及组态相互作用

Full-relativistic multi-configuration self-consistent calculation of atomic structures and physical properties——Construction of "quasi-complete basis sets" and configuration interaction calculations

从第一原理出发计算原子结构有多种理论方法,它们都是基于变分原理的,其关键是构建一组最适合描述真实物理体系的且适用于变分原理的准完备基.本文阐明了如何利用全相对论计算程序GRASPVU,通过单组态Dirac-Fock计算以及多组态Dirac-Fock自洽场计算建立准完备基.然后利用该准完备基进行组态相互作用计算以充分考虑关联作用;在此基础上,进一步考虑电磁相互作用的延迟效应和量子电动力学等修正.该准完备基对原子结构和电磁跃迁等物理量可进行精密的理论计算.最简单的He体系的能级和跃迁速率等物理量的计算值与目前最准确的理论计算值以及精密的实验测量值符合很好,验证了本文提出的方案的适用性.本文计算是全相对论的,可推广到相对论效应很重要的高Z类He体系,以面向重离子储存环相关实验测量.同时该方案也适用于其他任何多电子原子体系;对Mg进行了精密理论计算,阐明了其33D,43D精细结构次序变化的机理.

Based on the variation principle,many methods have been developed in atomic structure calculations.A high quality complete basis set is essential to the calculation of atomic structures.We present how to construct quasi-complete basis sets through Dirac-Fock calculations and multi-configuration Dirac-Fock self-consistent filed calculations by using the full-relativistic GRASPVU program package,which is based on the multi-configuration Dirac-Fock method.The relativistic configuration interaction calculations are carried out by using the quasi-complete basis sets to adequately consider correlations.The relativistic retardation effect of electromagnetic interactions and the quantum electron dynamic corrections are also taken into account.Our calculation results of He agree well with other theoretical results and experimental results,which validates the feasibility of our calculation scenario.Our calculations are full-relativistic,and can be extended to high Z helium-like ions in which the relativistic effect is important.Our scenario of constructing quasi-complete basis sets can be used in any many-electron atomic system.We calculated the energy levels of Mg and elucidated the mechanism of its interesting fine-structure splittings of 3 3D and 4 3D levels.