1. Relativistic equation-of-motion coupled-cluster method for the double-ionization potentials of closed-shell atoms.
- Author
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Pathak, Himadri, Ghosh, Aryya, Sahoo, B. K., Das, B. P., Vaval, Nayana, and Pal, Sourav
- Subjects
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IONIZATION (Atomic physics) , *T-matrix , *MATHEMATICAL physics , *NUMERICAL calculations , *PERTURBATION theory - Abstract
We report the implementation of the relativistic equation-of-motion coupled-cluster method to calculate the double-ionization spectra (DI-EOMCC) of the closed-shell atomic systems. This method is employed to calculate the principal valence double-ionization potential values of He and alkaline-earth-metal (Be, Mg, Ca, Sr, and Ba) atoms. Our results are compared with the results available from the NIST database and other ab initio calculations. We have achieved an accuracy of ~ 0.1 %, which is an improvement over the first-principles T-matrix calculations [Y. Noguchi et al., J. Chem. Phys. 123,144112 (2005)]. We also present results using the second-order many-body perturbation theory and the random-phase approximation in the equation-of-motion framework, and these results are compared with the DI-EOMCC results. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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