Approximate non-relativistic energy expression and the rotational–vibrational constants of the Tietz–Hua potential: a semiclassical approach

The low- and high-lying rovibrational energy levels of the Schrodinger equation with the molecular Tietz–Hua potential are obtained via the Wentzel–Kramers–Brilluoin (WKB) quantization approach. The Pekeris-type approximation scheme is applied to deal with the orbital centrifugal term of the effective potential function. The obtained energy spectra and the rotational–vibrational (rovibrational) coefficients for [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] diatomic molecules were compared with the ones obtained by other analytical methods and available experimental data in the literature. The results revealed that the accuracy of the energy spectra for the high-lying rovibrational quantum states may depend on the rotational-vibrational constants.

Electronic structure with dipole moment and rovibrational calculations of the MgLi and MgNa molecules

We investigate an orderly study of the adiabatic potential energy curves for 29 and 30 low-lying 2s+1Λ+/− electronic states of the molecules MgLi and MgNa, respectively. The calculation has been done by using the complete active space self-consistent field followed by multi-reference configuration interaction with Davidson correction. For the investigated electronic states, the static and transition dipole moment curves are calculated along with the Einstein coefficients, the emission oscillator strength, the spontaneous radiative lifetime, the line strength, the classical radiative decay rate of the single-electron oscillator, the spectroscopic constants (Te, ωe, ωexe, Be, Re), and the equilibrium dissociation energy De. By means of the canonical functions approach, the ro-vibrational constants Ev, Bv, Dv, and the abscissas of the turning points, Rmin and Rmax, have been calculated for the considered electronic states up to the vibrational level v = 79. The Franck–Condon factors have been calculated and plotted for the transition between the low-lying electronic states of the two considered molecules. A good agreement is revealed between our calculated values and those available in the literature. Fifty new electronic states are investigated in the present work for the first time.

Rovibrational Interaction and Vibrational Constants of the Symmetric Top Molecule14NF3

Several accurate experimental values of the and rotation-vibration interaction parameters and , , and vibrational constants have been extracted from the most recent high-resolution Fourier transform infrared, millimeter wave, and centimeter wave investigations in the spectra of the oblate symmetric top molecule14NF3. The band-centres used are those of the four fundamental, the overtones, the combination, and hot bands identified in the region between 400 cm−1and 2000 cm−1. Comparison of our constants with the ones measured previously, by infrared spectroscopy at low resolution, reveals orders of magnitude higher accuracy of the new values. The agreement between our values and those determined byab initiocalculations employing the TZ2Pf basis is excellent.