Summa F F, Andersen J H, Lazzeretti P, Sauer S P A, Monaco G, Coriani S, Zanasi R
DTU Chemistry, Technical University of Denmark, Kemitorvet Bldg. 207, DK-2800 Kongens Lyngby, Denmark.
Dipartimento di Chimica e Biologia "A. Zambelli", Università degli Studi di Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
J Chem Theory Comput. 2023 Oct 24;19(20):7242-7259. doi: 10.1021/acs.jctc.3c00753. Epub 2023 Oct 5.
The calculation of the origin-independent density of the dynamic electric dipole polarizability, previously presented for uncorrelated and density functional theory (DFT)-based methods, has been developed and implemented at the coupled cluster singles and doubles (CCSD) level of theory. A pointwise analysis of polarizability densities calculated for a number of molecules at Hartree-Fock (HF) and CCSD clearly shows that the electron correlation effect is much larger than one would argue considering the integrated dipole electric polarizability alone. Large error compensations occur during the integration process, which hide fairly large deviations mainly located in the internuclear regions. The same is observed when calculated CCSD and B3LYP polarizability densities are compared, with the remarkable feature that positive/negative deviations between CCSD and HF reverse sign, becoming negative/positive when comparing CCSD to B3LYP.
先前针对不相关和基于密度泛函理论（DFT）的方法提出的动态电偶极极化率的与原点无关密度的计算，已在耦合簇单双激发（CCSD）理论水平上得到发展和实现。对多个分子在哈特里 - 福克（HF）和CCSD水平下计算得到的极化率密度进行逐点分析，清楚地表明电子相关效应比仅考虑积分偶极电极化率时所认为的要大得多。在积分过程中会出现大的误差补偿，这掩盖了主要位于核间区域的相当大的偏差。当比较计算得到的CCSD和B3LYP极化率密度时也观察到同样的情况，显著的特征是CCSD与HF之间的正/负偏差会反转符号，在将CCSD与B3LYP比较时变为负/正。
