Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian

Imafuku, Yuji; Abe, Minori; Schmidt, Michael W.; Hada, Masahiko

doi:10.1021/acs.jpca.6b01507

Title: Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian

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Abstract

Methodologies beyond the Born–Oppenheimer (BO) approximation are nowadays important to explain high precision spectroscopic measurements. Most previous evaluations of the BO correction are, however, focused on light-element molecules and based on a nonrelativistic Hamiltonian, so no information about the BO approximation (BOA) breakdown in heavy-element molecules is available. The present work is the first to investigate the BOA breakdown for the entire periodic table, by considering scalar relativistic effects in the Diagonal BO correction (DBOC). In closed shell atoms, the relativistic EDBOC scales as Z^1.25 and the nonrelativistic EDBOC scales as Z^1.17, where Z is the atomic number. Hence, we found that EDBOC becomes larger in heavy element atoms and molecules, and the relativistic EDBOC increases faster than nonrelativistic EDBOC. We have further investigated the DBOC effects on properties such as potential energy curves, spectroscopic parameters, and various energetic properties. The DBOC effects for these properties are mostly affected by the lightest atom in the molecule. Furthermore, in X₂ or XAt molecule (X = H, Li, Na, K, Rb, and Cs) the effect of DBOC systematically decreases when X becomes heavier but in HX molecules, the effect of DBOC seems relatively similar among all the molecules.

Authors:

Imafuku, Yuji ^[1]; Abe, Minori ^[1]; Schmidt, Michael W. ^[2]; Hada, Masahiko ^[1]

Tokyo Metropolitan Univ., Tokyo (Japan)
Iowa State Univ., Ames, IA (United States)

Publication Date:: Tue Mar 22 00:00:00 EDT 2016

Research Org.:: Ames Lab., Ames, IA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1254324

Report Number(s):: IS-J-8976
Journal ID: ISSN 1089-5639

Grant/Contract Number:: AC02-07CH11358

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory

Additional Journal Information:: Journal Volume: 120; Journal Issue: 13; Journal ID: ISSN 1089-5639

Publisher:: American Chemical Society

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

Citation Formats


                    Imafuku, Yuji, Abe, Minori, Schmidt, Michael W., and Hada, Masahiko. Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian.  United States: N. p., 2016. 
Web.  doi:10.1021/acs.jpca.6b01507.

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                    Imafuku, Yuji, Abe, Minori, Schmidt, Michael W., & Hada, Masahiko. Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian.  United States.  https://doi.org/10.1021/acs.jpca.6b01507

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                    Imafuku, Yuji, Abe, Minori, Schmidt, Michael W., and Hada, Masahiko. Tue .  
"Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian".  United States.  https://doi.org/10.1021/acs.jpca.6b01507.  https://www.osti.gov/servlets/purl/1254324.

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@article{osti_1254324,

  title        = {Heavy element effects in the diagonal Born–Oppenheimer correction within a relativistic spin-free Hamiltonian},

  author       = {Imafuku, Yuji and Abe, Minori and Schmidt, Michael W. and Hada, Masahiko},

  abstractNote = {Methodologies beyond the Born–Oppenheimer (BO) approximation are nowadays important to explain high precision spectroscopic measurements. Most previous evaluations of the BO correction are, however, focused on light-element molecules and based on a nonrelativistic Hamiltonian, so no information about the BO approximation (BOA) breakdown in heavy-element molecules is available. The present work is the first to investigate the BOA breakdown for the entire periodic table, by considering scalar relativistic effects in the Diagonal BO correction (DBOC). In closed shell atoms, the relativistic EDBOC scales as Z1.25 and the nonrelativistic EDBOC scales as Z1.17, where Z is the atomic number. Hence, we found that EDBOC becomes larger in heavy element atoms and molecules, and the relativistic EDBOC increases faster than nonrelativistic EDBOC. We have further investigated the DBOC effects on properties such as potential energy curves, spectroscopic parameters, and various energetic properties. The DBOC effects for these properties are mostly affected by the lightest atom in the molecule. Furthermore, in X2 or XAt molecule (X = H, Li, Na, K, Rb, and Cs) the effect of DBOC systematically decreases when X becomes heavier but in HX molecules, the effect of DBOC seems relatively similar among all the molecules.},

  doi          = {10.1021/acs.jpca.6b01507},

  journal      = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},

  number       = 13,

  volume       = 120,

  place        = {United States},

  year         = {Tue Mar 22 00:00:00 EDT 2016},

  month        = {Tue Mar 22 00:00:00 EDT 2016}

}

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