Electronic structure of the ZnCl molecule with rovibrational and ionicity studies of the ZnX (X = F, Cl, Br, I) compounds

Abstract

Based on the complete active space self consistent field (CASSCF) method with multi-reference configuration interaction MRCI calculations including single and double excitations with Davidson correction (+Q), twenty three low lying electronic states in the 2s+1Λ(±) representation of the zinc monochloride ZnCl molecule are investigated considering 7 and 9 valence electrons. The internuclear distance Re, the harmonic frequency ωe, the permanent dipole moment μ, the rotational constant Be and the electronic transition energy with respect to the ground state Te are calculated for the bound states. The transition dipole moment between some doublet states is used to determine the Einstein spontaneous A21 and induced emission B21ω coefficients, the spontaneous radiative lifetime τspon, the emission wavelength λ21, the oscillator strength f21 and the line strength S21. The fraction of the ground state ionic character f and equilibrium dissociation energy DE,e are also computed. Using the canonical function approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv and the abscissas of the turning points Rmin and Rmax of the zinc monohalide molecules ZnX (X: F, Cl, Br, I) are calculated. The comparison between the values of the present work and those available in the literature for several electronic states shows good accordance.