Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
J Chem Phys. 2011 Jan 28;134(4):044102. doi: 10.1063/1.3547262.
All-electron correlation energies E(c) are not very well-known for atoms with more than 18 electrons. Hence, coupled-cluster calculations in carefully designed basis sets are combined with fully converged second-order Møller-Plesset perturbation theory (MP2) computations to obtain fairly accurate, nonrelativistic E(c) values for the 12 closed-shell atoms from Ar to Rn. These energies will be useful for the evaluation and parameterization of density functionals. The results show that MP2 overestimates ∣E(c)∣ for heavy atoms. Spin-component scaling of the MP2 correlation energy is used to provide a simple explanation for this overestimation.
对于超过 18 个电子的原子，全电子相关能量 E(c) 并不是很为人所知。因此，在精心设计的基组中结合完全收敛的二阶 Møller-Plesset 微扰理论（MP2）计算，以获得从 Ar 到 Rn 的 12 个满壳层原子相当准确的非相对论 E(c) 值。这些能量对于密度泛函的评估和参数化将是有用的。结果表明，MP2 高估了重原子的∣E(c)∣。MP2 相关能量的自旋分量缩放用于对此高估提供简单解释。
