Brito Bráulio Gabriel A, Hai G-Q, Teixeira Rabelo J N, Cândido Ladir
Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970, São Carlos, SP, Brazil.
Phys Chem Chem Phys. 2014 May 14;16(18):8639-45. doi: 10.1039/c4cp00416g.
Using fixed-node diffusion quantum Monte Carlo (FN-DMC) simulation we investigate the electron correlation in all-metal aromatic clusters MAl4(-) (with M = Li, Na, K, Rb, Cu, Ag and Au). The electron detachment energies and electron affinities of the clusters are obtained. The vertical electron detachment energies obtained from the FN-DMC calculations are in very good agreement with the available experimental results. Calculations are also performed within the Hartree-Fock approximation, density-functional theory (DFT), and the couple-cluster (CCSD(T)) method. From the obtained results, we analyse the impact of the electron correlation effects in these bimetallic clusters and find that the correlation of the valence electrons contributes significantly to the detachment energies and electron affinities, varying between 20% and 50% of their total values. Furthermore, we discuss the electron correlation effects on the stability of the clusters as well as the accuracy of the DFT and CCSD(T) calculations in the present systems.
我们使用固定节点扩散量子蒙特卡罗（FN-DMC）模拟方法研究了全金属芳香族簇合物MAl4(-)（其中M = Li、Na、K、Rb、Cu、Ag和Au）中的电子相关性。得到了这些簇合物的电子脱离能和电子亲和能。从FN-DMC计算中获得的垂直电子脱离能与现有的实验结果非常吻合。同时，我们也在哈特里-福克近似、密度泛函理论（DFT）和耦合簇（CCSD(T)）方法下进行了计算。根据所得结果，我们分析了电子相关效应在这些双金属簇合物中的影响，发现价电子的相关性对脱离能和电子亲和能有显著贡献，占其总值的20%至50%。此外，我们还讨论了电子相关效应对簇合物稳定性的影响以及DFT和CCSD(T)计算在本体系中的准确性。
