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.83968406 Abstract
 The A (1)Sigma(+) potential energy curve of AgH is studied by means of the secondorder multistate multireference perturbation theory including the spinorbit 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 46 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ioniclike [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 secondorder multistate multireference perturbation theory including the spinorbit 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 46 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ioniclike [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 Morselike covalent interaction between Ag and H, and the electrostatic ioniclike 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 statespecific calculations. Larger relative discrepancy is observed for omega(e)x(e), about 30 cm(1), however the nonMorselike 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:
http://lup.lub.lu.se/record/339562
 author
 Witek, HA; Fedorov, DG; Hirao, K; Viel, A and Widmark, PerOlof ^{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
 external identifiers

 wos:000175297600018
 scopus:0037088381
 ISSN
 00219606
 DOI
 10.1063/1.1465403
 language
 English
 LU publication?
 yes
 id
 c1e9e57786d84918a047e03137e06911 (old id 339562)
 date added to LUP
 20071109 16:01:55
 date last changed
 20170101 04:43:21
@article{c1e9e57786d84918a047e03137e06911, abstract = {The A (1)Sigma(+) potential energy curve of AgH is studied by means of the secondorder multistate multireference perturbation theory including the spinorbit 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 46 Angstrom, a partial electron transfer from the 5p(z) orbital of silver to the 1s orbital of hydrogen occurs. This admixture of the ioniclike [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 Morselike covalent interaction between Ag and H, and the electrostatic ioniclike 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 statespecific calculations. Larger relative discrepancy is observed for omega(e)x(e), about 30 cm(1), however the nonMorselike 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, PerOlof}, issn = {00219606}, language = {eng}, number = {19}, pages = {83968406}, publisher = {American Institute of Physics}, 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}, volume = {116}, year = {2002}, }