Vibrational transitions of H2Cl+: potential energy surface and anharmonic computations

A new three-dimensional potential energy surface of the electronic ground state of the chloronium ion, H2Cl+, based on the explic- itly correlated coupled cluster method with a triple zeta basis set adapted to this method has been expanded in an analytical rep- resentation. This potential energy surface is later incorporated into our home-made Fortran code to compute variationally the vibrational levels and zero-point ground average structural parameters of the chloronium ion, H2Cl+, and several isotopologues. Our results show an excellent agreement with experimental data and that our results will help to detect H2Cl+ isotopologues in the interstellar medium.