Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin, Poland and Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany.
J Chem Phys. 2013 Dec 14;139(22):224108. doi: 10.1063/1.4837179.
The weak-correlation asymptotics of electronic properties of harmonium atoms comprising up to four electrons are investigated. In particular, closed-form expressions are derived for the first- and second-order contributions to the Hartree-Fock and correlation energies of eight electronic states that include three singlets, one doublet, two triplets, one quartet, and one quintet, six of which are singly determinantal and two are multi-determinantal. This diversity of states offers a much richer set of benchmarking tools for calibration of approximate electron-correlation methods than the previously published data. The availability of the computed energy contributions due to individual spinorbitals and their pairs present in the dominant Slater determinants further enhances the utility of these benchmarks.
本文研究了包含多达四个电子的谐振子原子的电子性质的弱关联渐近。特别地，导出了八个电子态的 Hartree-Fock 和相关能量的一阶和二阶贡献的闭式表达式，其中包括三个单重态、一个双重态、两个三重态、一个四重态和一个五重态，其中六个是单行列式，两个是多行列式。与以前发表的数据相比，这些状态的多样性为校准近似电子相关方法提供了更丰富的基准测试工具。由于在主要 Slater 行列式中存在的单个自旋轨道及其对，因此可计算出能量贡献，这进一步增强了这些基准的实用性。
