Potential energy and dipole moment surfaces of H3- molecule

A new potential energy surface for the electronic ground state of the simplest triatomic anion H-3(-) is determined for a large number of geometries. Its accuracy is improved at short and large distances compared to previous studies. The permanent dipole moment surface of the state is also computed for the first time. Nine vibrational levels of H-3(-) and 14 levels of D-3(-) are obtained, bound by at most similar to 70 and similar to 126 cm(-1), respectively. These results should guide the spectroscopic search of the H-3(-) ion in cold gases (below 100K) of molecular hydrogen in the presence of H- ions. (C) 2010 American Institute of Physics. [doi:10.1063/1.3424847]