Modified Dunham potential for rovibrational diatomic systems

1995 ◽  
Vol 73 (1-2) ◽  
pp. 59-62 ◽  
Author(s):  
Marcin Molski ◽  
Jerzy Konarski
Keyword(s):  
Angular Momentum ◽  
Quantum Number ◽  
Standard Method ◽  
Diatomic Molecules ◽  
Rotational Quantum Number ◽  
Electronic States ◽  
Rotational States ◽  
Diatomic Systems ◽  
Rovibrational States ◽  
Rotational Angular Momentum

A modified Dunham potential with parameters depending on the rotational quantum number is employed to describe the rovibrational states of diatomic molecules. This approach, applied to H81Br, 115InD, 7LiH, and 40Ar2, gives satisfactory reproduction of the observed transitions using fewer Dunham parameters than in the standard method. The results obtained indicate the possibility of introducing the local internal potentials, which, in contradiction to the global ones usually used, depend on the rotational states of a rotating–vibrating molecule. Such a J dependence may be a result of rovibronic interactions, in particular, Coriolis-type nonadiabatic interactions coupling other electronic states through the rotational angular momentum.

The effect of collisions on the rotational angular momentum of diatomic molecules studied using polarized light

2020 ◽  
Vol 153 (18) ◽  
pp. 184310
Author(s):  
P. T. Arndt ◽  
J. Huennekens ◽  
C. Packard ◽  
V. Tran ◽  
J. Carey ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Diatomic Molecules ◽  
Polarized Light ◽  
Rotational Angular Momentum

A quasi-classical trajectory study of the reagent initial rotation quantum state effect on the reaction He + T2+ → HeT+ + T using an improved ab initio potential energy surface

2012 ◽  
Vol 90 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Ningjiu Zhao ◽  
Yufang Liu
Keyword(s):  
Angular Momentum ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Quantum Number ◽  
Relative Velocity ◽  
Energy Surface ◽  
Rotational Quantum Number ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Positive Direction

In this work, we employed the quasi-classical trajectory (QCT) method to study the vector correlations and the influence of the reagent initial rotational quantum number j for the reaction He + T2+ (v = 0, j = 0–3) → HeT+ + T on a new potential energy surface (PES). The PES was improved by Aquilanti co-workers (Chem. Phys. Lett. 2009. 469: 26–30). The polarization-dependent differential cross sections (PDDCSs) and the distributions of P(θr), P([Formula: see text]r), and P(θr, [Formula: see text]r) are presented in this work. The plots of the PDDCSs provide us with abundant information about the distribution of the product angular momentum polarization. The P(θr) is used to describe the correlation between k (the relative velocity of the reagent) and j′ (the product rotational angular momentum). The distribution of dihedral angle P([Formula: see text]r) shows the k–k′–j′ (k′ refers to the relative velocity of the product) correlation. The PDDCS calculations illustrate that the product of this reaction is mainly backward scatter and it has the strongest polarization in the backward and sideways scattering directions. At the same time, the results of the P([Formula: see text]r) demonstrate that the product HeT+ tends to be oriented along the positive direction of the y axis and it tends to rotate right-handedly in planes parallel to the scattering plane. Moreover, the distribution of the P(θr) manifests that the product angular momentum is aligned along different directions relative to k. The direction of the product alignment may be perpendicular, opposite, or parallel to k. Moreover, our calculations are independent of the initial rotational quantum number.

scholarly journals Rotation Effect in Morse Potential For K2 Molecule

2011 ◽  
Vol 8 (4) ◽  
pp. 968-971
Author(s):  
Baghdad Science Journal
Keyword(s):  
Quantum Number ◽  
Dissociation Energy ◽  
Effective Potential ◽  
Morse Potential ◽  
Rotational Quantum Number ◽  
Electronic States ◽  
Rotation Effect ◽  
Potential Curves

The rotation effect upon Morse potential had been studied and the values of the effective potential in potential curves had been calculated for electronic states (X2?+g , B ?u ) K2 molecule. The calculation had been computed for rotational quantum number (J = 5). Also, drawing potential curves for these systems had been done using Herzberg and Gaydon equations. It was found that the values of the dissociation energy which resulting from using Herzberg equation greater than that of Gaydon equation. Besides, it was found that the rotation effect for (X and B) electronic states in Morse potential is very small and in this case may negligible.

scholarly journals Emission Spectra for the Isotopic Molecule Lithium Hydride

2014 ◽  
Vol 11 (2) ◽  
pp. 535-539
Author(s):  
Baghdad Science Journal
Keyword(s):  
Spectral Line ◽  
Quantum Number ◽  
Rotational Quantum Number ◽  
Electronic States ◽  
Emission Spectra ◽  
Lithium Hydride ◽  
Spectral Lines ◽  
Isotopic Molecule

A study of the emission spectra of isotopic for electronic states has been carried out. The energies of the vibration levels ( =0,1,..25) and the values of spectral lines R(J) and P(J) versus rotational quantum number (J=0,1..25). It was found that were an increase of the value of R(J) with the increase of the values of J was found while the value of P(J) decreases with decreasing of the values of J . It was found that corresponding to R(J) and P(J) the spectral line R(J) increases when the values of m increased.

Rotational Angular Momentum Dependence of the Scattering Amplitude for Elastic Molecular Collisions

1968 ◽  
Vol 23 (12) ◽  
pp. 1903-1911 ◽  
Author(s):  
S. Hess ◽  
W. E. Köhler
Keyword(s):  
Angular Momentum ◽  
Interaction Potential ◽  
Scattering Amplitude ◽  
Diatomic Molecules ◽  
Spin Operator ◽  
Potential Functions ◽  
Momentum Dependence ◽  
Starting Point ◽  
Spin Tensors ◽  
Rotational Angular Momentum

The rotational angular momentum (spin) dependence of the binary scattering amplitude operator is investigated for elastic collisions of homonuclear diatomic molecules with monatomic and diatomic particles. Starting point is a formal expansion of the T-matrix (and consequently of the scattering amplitude) with respect to the nonsphericity parameter ε which essentially measures the ratio of the nonspherical and spherical parts of the interaction potential. A transscription of angle dependent potential functions into a spin operator notation is introduced. Potential functions and values for ε may be inferred from the data available in the literature for the interactions: H2—He (ε ≈ 1/4) and H2—H2 (ε ≈ 1/20). As far as elastic events are concerned, irreducible spin tensors of even rank only occur with the interaction potential and consequently with the scattering amplitude in order ε. The most important terms of the scattering amplitude of diatomic molecules are quadratic in the spins. These terms are discussed in detail. In order ε2 the scattering amplitude also contains irreducible spin tensors of odd rank. A knowledge of the orders of magnitude of the various spin — dependent terms is of interest for the SENFTLEBEN-BEENAKKER effect and for NMR in polyatomic gases.

Study of T2 relaxation for l-doublet transitions of OCS

1984 ◽  
Vol 62 (12) ◽  
pp. 1280-1285 ◽  
Author(s):  
S. C. Mehrotra ◽  
H. Mäder
Keyword(s):  
Quantum Number ◽  
Line Width ◽  
Pressure Dependence ◽  
Vibrational State ◽  
Rotational Quantum Number ◽  
Relaxation Times ◽  
T2 Relaxation ◽  
Excited Vibrational State ◽  
Transverse Relaxation ◽  
Rotational States

The pressure dependence of transverse relaxation times T2 has been measured for l-doublet transitions of OCS in the excited vibrational state (01 10) in rotational states with 29 ≤ J ≤ 42 by using the transient emission technique. The line width parameter decreases with an increase of rotational quantum number J from 6.54(12) MHz/Torr at J = 29 to 5.53(6) MHz/Torr at J = 42. The result has been compared with the results obtained from the modified Murphy–Boggs theory.

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