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)
Please use this url to cite or link to this publication:
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}},
}