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 explicitly correlated coupled cluster method with a triple zeta basis set adapted to this method has been expanded in an analytical representation. This potential energy surface is later incorporated into our home-made Fortran code to compute variationally the vibrational levels, zero-point ground average structural parameters and the rotational constants of the chloronium ion and several isotopologues. Our results show a good agreement with experimental data and that our results will help to detect H2Cl+ isotopologues in the interstellar medium.