Study of the radiative transitions in the molecular ion SiH + : potential energy curves, spectroscopic constants and transition probabilities

Radiative transitions between the bound states of the molecular cation SiH+were studied. To achieve this, potential energy curves of the SiH+ cation were obtained at the MRCI/cc-PV6Z level of theory. Using these PECs, spectroscopic constants were obtained, including the equilibrium bond length (Re), rotational-vibrational constants (αe), rotational constant (Be), harmonic frequency (ωe), first- and second-order anharmonicity constants (ωexe, ωeye) and centrifugal distortion constant (De) were obtained by fitting the Morse potential. Our results show good agreement with existing experimental and theoretical values. Transition dipole moments were calculated and used to determine molecular parameters such as oscillator strength (fv′v), r-centroids (rv′v ), Einstein coefficients (Av′v), radiative lifetimes (τv′v), and Franck-Condon factors (qv′v). Additionally, spin-orbit calculations were performed to predict local perturbations in certain states, as well as to elucidate the polarity of the SiH+ in its various electronic states. This study could be of great practical interest in astrophysical research and laboratory experiments.