Theoretical study of the unusual potential energy curve of the A (1)Sigma(+) state of AgH
(2002) In Journal of Chemical Physics 116(19). p.8396-8406- Abstract
- The A (1)Sigma(+) potential energy curve of AgH is studied by means of the second-order multistate multireference perturbation theory including the spin-orbit and relativistic effects. The anomalous behavior of the vibrational energy levels observed in experiment is reproduced well by theory. An analysis of the A (1)Sigma(+) wave function shows that at the internuclear distance of 4-6 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ionic-like [core] 4d(10)1s(H)(2) configuration occurring in A (1)Sigma(+) due to two avoided crossings, namely X (1)Sigma(+) with A (1)Sigma(+) and A (1)Sigma(+) with C (1)Sigma(+), is found to be responsible for the unusual shape... (More)
- The A (1)Sigma(+) potential energy curve of AgH is studied by means of the second-order multistate multireference perturbation theory including the spin-orbit and relativistic effects. The anomalous behavior of the vibrational energy levels observed in experiment is reproduced well by theory. An analysis of the A (1)Sigma(+) wave function shows that at the internuclear distance of 4-6 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ionic-like [core] 4d(10)1s(H)(2) configuration occurring in A (1)Sigma(+) due to two avoided crossings, namely X (1)Sigma(+) with A (1)Sigma(+) and A (1)Sigma(+) with C (1)Sigma(+), is found to be responsible for the unusual shape of the A (1)Sigma(+) potential energy curve: the effective potential is a superposition of a Morse-like covalent interaction between Ag and H, and the electrostatic ionic-like interaction between Ag+ and H-. We present spectroscopic parameters, vibrational levels, and rotational constants computed for a large number of vibrational levels and observe good agreement with available experimental data. The equilibrium distance agrees within 0.01 Angstrom and the vibrational frequency within 60 cm(-1) for the state-specific calculations. Larger relative discrepancy is observed for omega(e)x(e), about 30 cm(-1), however the non-Morse-like nature of the energy curve makes it impossible to describe the levels only with omega and omega(e)x(e), so that direct comparison is not well defined. (Less)
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https://lup.lub.lu.se/record/339562
- author
- Witek, HA ; Fedorov, DG ; Hirao, K ; Viel, A and Widmark, Per-Olof LU
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Chemical Physics
- volume
- 116
- issue
- 19
- pages
- 8396 - 8406
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- wos:000175297600018
- scopus:0037088381
- ISSN
- 0021-9606
- DOI
- 10.1063/1.1465403
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)
- id
- c1e9e577-86d8-4918-a047-e03137e06911 (old id 339562)
- date added to LUP
- 2016-04-01 11:58:45
- date last changed
- 2023-01-03 02:09:28
@article{c1e9e577-86d8-4918-a047-e03137e06911, abstract = {{The A (1)Sigma(+) potential energy curve of AgH is studied by means of the second-order multistate multireference perturbation theory including the spin-orbit and relativistic effects. The anomalous behavior of the vibrational energy levels observed in experiment is reproduced well by theory. An analysis of the A (1)Sigma(+) wave function shows that at the internuclear distance of 4-6 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ionic-like [core] 4d(10)1s(H)(2) configuration occurring in A (1)Sigma(+) due to two avoided crossings, namely X (1)Sigma(+) with A (1)Sigma(+) and A (1)Sigma(+) with C (1)Sigma(+), is found to be responsible for the unusual shape of the A (1)Sigma(+) potential energy curve: the effective potential is a superposition of a Morse-like covalent interaction between Ag and H, and the electrostatic ionic-like interaction between Ag+ and H-. We present spectroscopic parameters, vibrational levels, and rotational constants computed for a large number of vibrational levels and observe good agreement with available experimental data. The equilibrium distance agrees within 0.01 Angstrom and the vibrational frequency within 60 cm(-1) for the state-specific calculations. Larger relative discrepancy is observed for omega(e)x(e), about 30 cm(-1), however the non-Morse-like nature of the energy curve makes it impossible to describe the levels only with omega and omega(e)x(e), so that direct comparison is not well defined.}}, author = {{Witek, HA and Fedorov, DG and Hirao, K and Viel, A and Widmark, Per-Olof}}, issn = {{0021-9606}}, language = {{eng}}, number = {{19}}, pages = {{8396--8406}}, publisher = {{American Institute of Physics (AIP)}}, series = {{Journal of Chemical Physics}}, title = {{Theoretical study of the unusual potential energy curve of the A (1)Sigma(+) state of AgH}}, url = {{http://dx.doi.org/10.1063/1.1465403}}, doi = {{10.1063/1.1465403}}, volume = {{116}}, year = {{2002}}, }