First and second derivative of the wave function of the {sup 1}{Sigma}{sup +} states of the KH molecule

Journal Article · Fri Apr 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.042502· OSTI ID:21544609

Khelifi, Neji ^[1]

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1. King Saud University, College of Science, Physics and Astronomy Department, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

First and second derivative of the nonadiabatic coupling between the several {sup 1}{Sigma}{sup +} adiabatic states of the KH molecule considered from accurate diabatic and adiabatic data have been evaluated. Such derivatives of the electronic wave function are determined through a numerical differentiation of the rotational matrix connecting the diabatic and adiabatic representations. The first as well as the second derivative present many peaks related to ionic-neutral and neutral-neutral coupling between the {sup 1}{Sigma}{sup +} states. Such radial coupling has been exploited to calculate the first adiabatic correction, which corresponds to the diagonal term of the second derivative divided by the reduced mass, for the ground and some excited states of the KH molecule. The second adiabatic correction has been determined using the virial theorem. The first adiabatic correction was added to the adiabatic potential energy curves to redetermine the corrected spectroscopic constants and vibrational energy levels. The vibrational shift, which is the difference between the corrected and the adiabatic levels, has been calculated for X, A, C, and D {sup 1}{Sigma}{sup +} states of the KH molecule. A shift of some 10 cm{sup -1} is observed for some vibrational levels showing the breakdown of the Born-Oppenheimer approximation.

• OSTI ID: 21544609
• Journal Information: Physical Review. A, Vol. 83, Issue 4; Other Information: DOI: 10.1103/PhysRevA.83.042502; (c) 2011 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADIABATIC PROCESSES
BORN-OPPENHEIMER APPROXIMATION
CORRECTIONS
COUPLING
EXCITED STATES
MOLECULES
POTASSIUM HYDRIDES
POTENTIAL ENERGY
VIRIAL THEOREM
WAVE FUNCTIONS
ALKALI METAL COMPOUNDS
APPROXIMATIONS
CALCULATION METHODS
ENERGY
ENERGY LEVELS
FUNCTIONS
HYDRIDES
HYDROGEN COMPOUNDS
POTASSIUM COMPOUNDS