Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry; Michigan State University
Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry
Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry; Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy
Several coupled-cluster approaches with an approximate treatment of connected triply or quadruply excited clusters, including the CCSD(T), CCSD(2)T, and CR-CC(2,3) corrections to CCSD, the active-space CCSDt and CCSDTq methods, and the CC(t;3) and CC(q;4) corrections to CCSDt and CCSDTq derived using the CC(P;Q) framework, and their CCSDT and CCSDTQ parents are applied to the ground-state potential curve and vibrational term values of the magnesium dimer. The correlation-consistent aug-cc-pV(n+d)Z and aug-cc-pwCVnZ (n = T and Q) basis sets are used. Among the noniterative triples corrections to CCSD, the CR-CC(2,3) approach performs the best, but, in analogy to the previously studied beryllium dimer [I. Magoulas et al., J. Phys. Chem. A 122, 1350 (2018)], the CC(t;3) and CC(q;4) methods outperform other employed approaches in reproducing the CCSDT and CCSDTQ data. Composite calculations combining the nearly all-electron CCSDT and valence CC(q;4) and CCSDTQ computations reproduce the experimentally resolved part of the vibrational spectrum of Mg2 to within ~1 cm-1 when the vibrational spacings are examined, while predicting five extra vibrational states near the dissociation threshold, which have not been experimentally resolved. The corresponding binding energies and equilibrium bond lengths are within a few cm-1 and 0.01 A from their experimentally derived values.
Yuwono, Stephen H., et al. "Application of the coupled-cluster CC( <em>P</em> ; <em>Q</em> ) approaches to the magnesium dimer." Molecular Physics, vol. 117, no. 9-12, Jan. 2019. https://doi.org/10.1080/00268976.2018.1564847
Yuwono, Stephen H., Magoulas, Ilias, Shen, Jun, & Piecuch, Piotr (2019). Application of the coupled-cluster CC( <em>P</em> ; <em>Q</em> ) approaches to the magnesium dimer. Molecular Physics, 117(9-12). https://doi.org/10.1080/00268976.2018.1564847
Yuwono, Stephen H., Magoulas, Ilias, Shen, Jun, et al., "Application of the coupled-cluster CC( <em>P</em> ; <em>Q</em> ) approaches to the magnesium dimer," Molecular Physics 117, no. 9-12 (2019), https://doi.org/10.1080/00268976.2018.1564847
@article{osti_1593461,
author = {Yuwono, Stephen H. and Magoulas, Ilias and Shen, Jun and Piecuch, Piotr},
title = {Application of the coupled-cluster CC( <em>P</em> ; <em>Q</em> ) approaches to the magnesium dimer},
annote = {Several coupled-cluster approaches with an approximate treatment of connected triply or quadruply excited clusters, including the CCSD(T), CCSD(2)T, and CR-CC(2,3) corrections to CCSD, the active-space CCSDt and CCSDTq methods, and the CC(t;3) and CC(q;4) corrections to CCSDt and CCSDTq derived using the CC(P;Q) framework, and their CCSDT and CCSDTQ parents are applied to the ground-state potential curve and vibrational term values of the magnesium dimer. The correlation-consistent aug-cc-pV(n+d)Z and aug-cc-pwCVnZ (n = T and Q) basis sets are used. Among the noniterative triples corrections to CCSD, the CR-CC(2,3) approach performs the best, but, in analogy to the previously studied beryllium dimer [I. Magoulas et al., J. Phys. Chem. A 122, 1350 (2018)], the CC(t;3) and CC(q;4) methods outperform other employed approaches in reproducing the CCSDT and CCSDTQ data. Composite calculations combining the nearly all-electron CCSDT and valence CC(q;4) and CCSDTQ computations reproduce the experimentally resolved part of the vibrational spectrum of Mg2 to within ~1 cm-1 when the vibrational spacings are examined, while predicting five extra vibrational states near the dissociation threshold, which have not been experimentally resolved. The corresponding binding energies and equilibrium bond lengths are within a few cm-1 and 0.01 A from their experimentally derived values.},
doi = {10.1080/00268976.2018.1564847},
url = {https://www.osti.gov/biblio/1593461},
journal = {Molecular Physics},
issn = {ISSN 0026-8976},
number = {9-12},
volume = {117},
place = {United States},
publisher = {Taylor & Francis},
year = {2019},
month = {01}}