Spectroscopic constants and anharmonic force field of thiirane: a theoretical study

The potential interstellar medium molecule, thiirane, has received considerable attention of experimental and theoretical studies in recent years. The anharmonic force field and spectroscopic constants of thiirane are calculated using CCSD(T) and B3LYP methods employing correlation consistent basis sets. Molecular structure, ground state rotational constants, quartic and sextic centrifugal distortion constants, and fundamental frequencies of thiirane are compared with the available experimental data. The B3LYP and CCSD(T) results can reproduce them well. The rotational parameters and vibrational wave numbers of isotopologues for thiirane are also determined using B3LYP method. The new data obtained in this study might be used to assist astronomical search for thiirane.