Theoretical investigation for spectroscopic constants of ground-state alkaline-earth dimers with high accuracy
Theoretical investigation for spectroscopic constants of ground-state alkaline-earth dimers with high accuracy
复制标题
高精度基态碱土二聚体光谱常数的理论研究
DOI：
10.1007/s00214-012-1117-y
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发表时间：
2012-02
影响因子：
1.7
通讯作者：
Wang, Fan
中科院分区：
文献类型：
--
作者：
Yang, Dong-Dong;Wang, Fan
在这项工作中，我们提供了高度准确的理论估计基态碱土金属二聚体（钙，锶，钡）的光谱常数。用耦合团簇方法在单、双和非迭代三重激发[CCSD（T）]水平上计算了电子相关能，并在CCSDT和CCSDT（Q）水平上考虑了全三重和四重激发的影响.我们的研究结果表明，高阶电子相关是重要的，以实现高精度的结果。我们还发现，结果与平衡校正，这是为了消除基组叠加误差，偏离进一步远离那些在完整的基组限制比未校正的。计算得到的Ca2+和Sr2+的结合能和平衡键长与最近的实验数据吻合得很好。另一方面，我们对Ba2的结果与以前的理论数据有很大差异，并且没有可用的实验平衡键长和结合能进行校准。基于所采用的方法对Ca2和Sr2的性能，我们的结果应该是更可靠的，可能有助于未来的调查。
In this work, we provide highly accurate theoretical estimates for spectroscopic constants of the ground-state alkaline-earth dimers (Ca2, Sr2, and Ba2). Electron correlation energies are calculated with coupled-cluster method at the single, double, and noniterative triple excitations [CCSD(T)] level, and the effects of full triples as well as quadruple excitations are also taken into account at the CCSDT and the CCSDT(Q) level. Our results demonstrate that high-order electron correlation is important to achieve results with high accuracy. We also find that results for Ca2with counterpoise corrections, which are designed to eliminate the basis set superposition error, deviate further away from those at the complete basis set limit than the uncorrected ones. The calculated binding energies and equilibrium bond lengths for Ca2and Sr2are in excellent agreement with recent experimental data. On the other hand, our results for Ba2are quite different from previous theoretical data, and there is no available experimental equilibrium bond length and binding energy for calibration. Based on the performance of the adopted approach for Ca2and Sr2, our results should be more reliable and could be helpful for future investigations.
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DOI：
10.1140/epjd/e2003-00208-4
发表时间：
2003-10
期刊：
The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics
影响因子：
--
作者：
O. Allard;C. Samuelis;A. Pashov;H. Knöckel;E. Tiemann
通讯作者：
O. Allard;C. Samuelis;A. Pashov;H. Knöckel;E. Tiemann
影响因子：
2.9
作者：
U. Dammalapati;I. Norris;C. Burrows;A. Arnold;E. Riis
通讯作者：
U. Dammalapati;I. Norris;C. Burrows;A. Arnold;E. Riis
DOI：
10.1103/physrevb.43.6376
发表时间：
1991-03
期刊：
Physical review. B, Condensed matter
影响因子：
--
作者：
Ortíz;Ballone
通讯作者：
Ortíz;Ballone
影响因子：
2.9
作者：
Yixuan Wang;H. Flad;M. Dolg
通讯作者：
Yixuan Wang;H. Flad;M. Dolg
影响因子：
2.9
作者：
B. Bussery-Honvault;J. Launay;R. Moszynski
通讯作者：
B. Bussery-Honvault;J. Launay;R. Moszynski