Effective potential energy curves of the ground electronic state of CH+

Abstract

This study presents effective (mass-dependent) potential energy curves for the methylidyne cation, which reproduce highly accurately all the available spectral data and allow for evaluation of reliable ro-vibrational wavefunctions of the probed isotopomers. The ro-vibrational wavefunctions are then used to average ab initio calculated radial functions of the rotational g-factor and spin-rotation constants yielding rotational and vibrational matrix elements of these properties for specific ro-vibrational states or transition moments for all isotopomers. The results can be of use in answering open questions concerning the formation/destruction of CH(+) in the interstellar medium and in the assignment of Zeeman or hyperfine splittings in rotational spectra of CH(+).

The First Laboratory Detection of Vibration-rotation Transitions of 12CH+ and 13CH+ and Improved Measurement of Their Rotational Transition Frequencies

“…Regarding transition intensities, Follmeg et al (1987) calculated the permanent electrical dipole moment of CH + to be µ 0 = 1.679 D, and the transition dipole moment for the v = 1 − 0 band µ 1−0 = 0.016 D. These values are in reasonable agreement with those derived from Sauer & Špirko (2013) of 1.7 D and 0.0196 D, respectively. Cheng et al (2007) calculated µ 0 = 1.683 D, but they did not derive a vibrational transition moment.…”

R-matrix study of electron impact excitation and dissociation of CH+ions

“…Better calculations were performed by Kowalski and Piecuch (2001) and Barinvos and van Hemert (2004) though both were restricted to the singlet states only. Sauer and S ̆pirko (2013) obtained PECs of the ground and several excited states of CH + which reproduced available spectroscopic data with high accuracy. More recently, a comprehensive set of CH + curves of singlet, triplet and quintet symmetries were obtained by Biglari et al (2014) using the multireference configuration interaction (MRCI) method with large basis sets.…”

Reduced Radial Curves of Diatomic Molecules

“…The ro-vibrational wave functions | vJ > are obtained by solving the Schrödinger equation for the following effective ro-vibrational Hamiltonian for an isolated 1 Σ + state H eff = prefix− ℏ 2 2 μ d normald r ( 1 + g v false( r false) ) d normald r + ℏ 2 2 μ r 2 ( 1 + g r false( r false) ) J ( J + 1 ) + V BO ( r ) + V ′ ( r ) where V BO is the “mass-independent” part of the molecular potential energy curve (assumed to include the Born–Oppenheimer and relativistic terms) and the terms V ′( r ), g r ( r ), and g v ( r ) account for QED, residual retardation, adiabatic, and nonadiabatic effects. The sum V eff = V BO ( r ) + V ′( r ) is assumed to be determinable by fitting to the experimental data available; relying on the results obtained in refs , , the rotational g r ( r ) factor function is tentatively expressed as g r ( r ) = g 0 + g 1 ( r – r e )/( r + r e ) 2 , where g 0 and g 1 are fitting parameters and the vibrational g -factor g v ( r ) is neglected.…”