Dissociation energies and potential energy functions for the ground X {sup 1}Σ{sup +} and “avoidedcrossing” A {sup 1}Σ{sup +} states of NaH
Abstract
A directpotentialfit analysis of all accessible data for the A {sup 1}Σ{sup +} − X {sup 1}Σ{sup +} system of NaH and NaD is used to determine analytic potential energy functions incorporating the correct theoretically predicted longrange behaviour. These potentials represent all of the data (on average) within the experimental uncertainties and yield an improved estimate for the groundstate NaH well depth of D{sub e} = 15797.4 (±4.3) cm{sup −1}, which is ∼20 cm{sup −1} smaller than the best previous estimate. The present analysis also yields the first empirical determination of centrifugal (nonadiabatic) and potentialenergy (adiabatic) BornOppenheimer breakdown correction functions for this system, with the latter showing that the Astate electronic isotope shift is −1.1(±0.6) cm{sup −1} going from NaH to NaD.
 Authors:
 Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
 Publication Date:
 OSTI Identifier:
 22410270
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; BORNOPPENHEIMER APPROXIMATION; DISSOCIATION ENERGY; GROUND STATES; POTENTIAL ENERGY; SODIUM HYDRIDES
Citation Formats
Walji, SadruDean, Sentjens, Katherine M., and Le Roy, Robert J. Dissociation energies and potential energy functions for the ground X {sup 1}Σ{sup +} and “avoidedcrossing” A {sup 1}Σ{sup +} states of NaH. United States: N. p., 2015.
Web. doi:10.1063/1.4906086.
Walji, SadruDean, Sentjens, Katherine M., & Le Roy, Robert J. Dissociation energies and potential energy functions for the ground X {sup 1}Σ{sup +} and “avoidedcrossing” A {sup 1}Σ{sup +} states of NaH. United States. doi:10.1063/1.4906086.
Walji, SadruDean, Sentjens, Katherine M., and Le Roy, Robert J. 2015.
"Dissociation energies and potential energy functions for the ground X {sup 1}Σ{sup +} and “avoidedcrossing” A {sup 1}Σ{sup +} states of NaH". United States.
doi:10.1063/1.4906086.
@article{osti_22410270,
title = {Dissociation energies and potential energy functions for the ground X {sup 1}Σ{sup +} and “avoidedcrossing” A {sup 1}Σ{sup +} states of NaH},
author = {Walji, SadruDean and Sentjens, Katherine M. and Le Roy, Robert J.},
abstractNote = {A directpotentialfit analysis of all accessible data for the A {sup 1}Σ{sup +} − X {sup 1}Σ{sup +} system of NaH and NaD is used to determine analytic potential energy functions incorporating the correct theoretically predicted longrange behaviour. These potentials represent all of the data (on average) within the experimental uncertainties and yield an improved estimate for the groundstate NaH well depth of D{sub e} = 15797.4 (±4.3) cm{sup −1}, which is ∼20 cm{sup −1} smaller than the best previous estimate. The present analysis also yields the first empirical determination of centrifugal (nonadiabatic) and potentialenergy (adiabatic) BornOppenheimer breakdown correction functions for this system, with the latter showing that the Astate electronic isotope shift is −1.1(±0.6) cm{sup −1} going from NaH to NaD.},
doi = {10.1063/1.4906086},
journal = {Journal of Chemical Physics},
number = 4,
volume = 142,
place = {United States},
year = 2015,
month = 1
}

Coupled nonidentical microdisks: Avoided crossing of energy levels and unidirectional farfield emission
We investigate two coupled microdisks with nonidentical radii focusing on the parametric evolution of energy levels and the unidirectional farfield emission. We show that the evolution of energy levels is characterized by the avoided crossing intrinsically associated with the exceptional point or the nonHermitian degeneracy. These spectral properties explain highly asymmetric nearfield intensity pattern of the resonance mode. The observed unidirectional farfield emission is shown to be understood by considering the forbidden interdisk coupling in the ray picture induced by the frustrated total internal reflection near the closest point between two disks when the interdisk distance is small enough. 
Electronic structure and dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ from relativistic effective potential calculations
The dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ were computed using a generalization of the molecular relativistic ..omega....omega.. coupling formalism of Lee, Ermler, and Pitzer. Relativistic effects, as represented by the Dirac equation, were introduced using effective potentials generated from atomic DiracnFock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. Our calculations show that the ground state of Tl/sub 2//sup +/ is 1/2/sub g/ with computed D/sub e/ and R/sub e/ values of 0.58 eV and 3.84 A. For Tl/sub 2/ we find that the groundmore » 
Stark resonances of the Yukawa potential: Energies and widths, crossings and avoided crossings
The resonance energy spectrum of a system interacting with the Yukawa potential and embedded in an external homogeneous and static electric field is investigated. The positions and widths of levels have been computed by using the complex coordinate rotation method. Interesting avoidedcrossing and crossing effects appear.