Calculation of the interaction potential energy curve and vibrational levels for the state of molecule

The B′2Σ+ → X2Σ+ systems in MgH and MgD have been studied in emission at high resolution. Vibrational and rotational analyses, which have been performed for 37 bands of MgH and 16 bands of MgD, provide data on the following vibrational levels of the B′ state: MgH, ν = 0–9; MgD, ν = 0–2, 4–6. The following molecular constants (in cm−1) have been determined for the B′ state: MgH, Tc = 22 410, ωc = 828.4, ωcxc = 11.8, Bc = 2.585, Dc = 1.2 × 10−4; MgD, Tc = 22 415, ωc = 598.1, ωcxc = 6.4, Bc = 1.346, Dc = 2.6 × 10−5. The dissociation energy, Dc, in the B′ state is estimated to be 10 900 cm−1 (MgH), 11 200 cm−1 (MgD). The RKR potential energy curve for the B′ state has been calculated. A correlation of the rotational perturbations in the B′ → X system with the positions of rotational energy levels in the A2Π and B′2Σ+ states has been made. Observations for the low-lying states of MgH are compared with similar available data for related hydrides.

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New ab initio Potential Energy Curve and Vibrational Levels for the B1Σu+ State of the Hydrogen Molecule

Canadian Journal of Physics ◽

10.1139/p75-265 ◽

1975 ◽

Vol 53 (19) ◽

pp. 2189-2197 ◽

Cited By ~ 61

Author(s):

W. Kotos ◽

L. Wolniewicz

Keyword(s):

Wave Function ◽

Potential Energy ◽

Hydrogen Molecule ◽

Potential Energy Curve ◽

Energy Curve ◽

Elliptic Coordinates ◽

Dissociation Energies ◽

Vibrational Levels ◽

Nonadiabatic Effects ◽

Experimental Values

The Born–Oppenheimer potential energy curve for the B1Σu+ state of the hydrogen molecule has been computed using a wave-function in the form of an 88 term expansion in elliptic coordinates and including the interelectronic distance. At R = Re the computed energy is 5.2 cm−1 lower than the previous most accurate value, in agreement with the prediction by Dabrowski and Herzberg. The new potential energy curve, with the previously computed adiabatic corrections, has been used to calculate the vibrational levels for H2, HD, and D2. The resulting dissociation energies differ from the experimental values by less than 1 cm−1. The discrepancies between the theoretical and experimental energies for various vibrational levels amount up to 12 cm−1 for H2 and 8 cm−1 for D2. Their analysis suggests that most of the discrepancy is due to the nonadiabatic effects, but partly also to incomplete convergence of the Born–Oppenheimer potential energy curve, especially at large internuclear separations.

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Relationship of the deformed hyperbolic Kratzer-like and Tietz potential energy models for diatomic molecules

Canadian Journal of Physics ◽

10.1139/cjp-2013-0684 ◽

2014 ◽

Vol 92 (10) ◽

pp. 1258-1261 ◽

Cited By ~ 1

Author(s):

Chun-Sheng Jia ◽

Liang-Zhong Yi ◽

Shi-Wen Long

Keyword(s):

Potential Energy ◽

Potential Model ◽

Potential Energy Curve ◽

Diatomic Molecules ◽

Energy Curve ◽

Equilibrium Bond Length ◽

Energy Models ◽

Interaction Potential Energy ◽

Tietz Potential ◽

Relationship Of

Taking the dissociation energy and the equilibrium bond length as explicit parameters, we construct an improved form of the deformed hyperbolic Kratzer-like potential function for diatomic molecules. We show that the deformed hyperbolic Kratzer-like potential model is equivalent to the Tietz potential model for diatomic molecules. We observe that the Tietz potential is superior to the Morse potential in reproducing the interaction potential energy curve for the 23Πg state of the 7Li2 molecule.

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